优

完善媒体维护、备份恢复与播放诊断

cmd/server/application.go

@@ -79,6 +79,9 @@ func (a *application) start() error {
 		}
 	}
 
+	if err := database.ApplyPendingSQLiteRestore(context.Background(), a.cfg, a.logger); err != nil {
+		return fmt.Errorf("apply pending database restore: %w", err)
+	}
 	db, err := database.Open(a.cfg, a.logger)
 	if err != nil {
 		a.logger.Error("database open failed", zap.Error(err))

docs/superpowers/plans/2026-10-21-playback-correctness-isolation.md

@@ -0,0 +1,46 @@
+# Playback Correctness and Isolation Implementation Plan
+
+**Goal:** Fix the five playback defects from the 2026-10-21 review and make playback capability queries side-effect-free, without replacing the player or adding dependencies.
+
+**Scope:** The user approved implementing the reviewed fixes. Work in the current clean checkout; do not commit, push, deploy, or alter unrelated files.
+
+## Design and invariants
+
+- Keep existing media IDs, stream routes, direct playback and external-player URLs compatible.
+- Add optional `session_id` to local HLS requests. Authenticated handlers supply the actual user identity; a client parameter never supplies the owner. New web playback sessions use random IDs. Legacy clients are isolated by user and, where available, Emby play-session/device identity.
+- Keep transcoder media lookup/logging separate from its internal task key. A task key incorporates user, media and playback session. Each actual ffmpeg run writes to a fresh generation directory, so delayed segment requests never read a replacement run's output.
+- Stop only the authenticated caller's playback session. Check media visibility and scoped playback tokens on stop, just as on playlist/segment requests. Segment and playlist queries must match the running generation.
+- Cloud child requests resolve their real session media first, compare query media, enforce token scope and visibility against the real media, and reject mismatches before upstream fetch.
+- Treat player business positions as absolute source seconds. Only local HLS converts to/from a relative ffmpeg timeline.
+- Invalidate outstanding cloud-transcode requests on media/unmount, explicit source/quality changes, and newer requests. Guard both fulfilled and rejected responses.
+- Select local fallbacks only from available local qualities. Keep the existing 115-first preference when a cloud quality is available.
+- `PlaybackInfo` only reads capabilities/status. Explicit `StartTranscode` requests enqueue cloud work. Retain pending/ready response contracts, polling, and retries.
+
+## Tasks
+
+1. Add regression tests for local-scope isolation, stale generations, stop authorization, cloud media binding, pure capability reads, timeline conversion, available-local selection and stale async results. Run tests before implementation and verify the intended failures.
+2. Add tested playback helpers; route skip/undo/progress/quality/subtitle calculations through the common absolute timeline; guard cloud transcode results and fix local fallback choice.
+3. Extend existing transcoder/stream methods with an optional scope, preserve legacy internal calls, isolate task keys/output directories, and pass caller scope from web and Emby handlers. Bind web local HLS URLs and stop requests to captured session IDs.
+4. Enforce real-media authorization on cloud child requests and authenticated ownership on local stop.
+5. Split read-only cloud capability lookup from explicit cloud enqueue. Update existing cloud tests to use the explicit start operation and test no push during reads.
+6. Run focused and full Go tests, frontend tests, TypeScript/Vite build, lint diagnostics and review the diff for security, lifecycle and API compatibility. Fix regressions before reporting completion.
+
+## Verification commands
+
+- `node --experimental-strip-types --test src/pages/hlsPlayback.test.ts src/pages/directPlaySeek.test.ts src/pages/playerPageModel.test.ts src/pages/playbackQuality.test.ts src/pages/playbackRequestGuard.test.ts src/utils/skipSegments.test.ts`
+- `go test ./internal/service ./internal/handler ./internal/middleware -count=1`
+- `go test ./...`
+- `npm run build` and targeted ESLint for changed frontend files.
+
+## Out of scope
+
+New remux/audio-only ffmpeg pipelines, speculative browser codec policy changes, player replacement, broad UI refactors, performance improvement claims without measurements, and production deployment.
+
+## Verification outcome
+
+- Six frontend playback regression scripts pass; targeted ESLint and the TypeScript/Vite production build pass. The existing bundle-size warning remains.
+- Playback/stream/transcode/progress tests in service, handler and middleware pass, including scoped output reads, stale generation rejection, scoped stops, device-to-segment propagation, read-only capability queries and concurrent cloud start deduplication.
+- Whole-repository tests pass with only `TestQueueLibraryRootScanImportsNewLibraryMedia` and `TestSQLiteRestoreStagesWithoutChangingLiveDatabase` excluded. Both were run independently and reproduce Windows file-lock / SQLite errors in unmodified scan/database code. They are not silently disabled in source.
+- FFmpeg is not installed in this environment, so the existing real-transcode lifecycle test skips. Actual video, upstream 115 and browser end-to-end playback remain unverified.
+- Clients with no playback-session or device identifier retain per-user legacy isolation; new web requests always carry an independent session ID.
+- No commit, push or deployment was performed.

internal/database/sqlite_restore.go

@@ -0,0 +1,189 @@
+package database
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"io"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+
+	"go.uber.org/zap"
+
+	"github.com/truewhile/MeBox/internal/config"
+)
+
+var sqliteRestoreMu sync.Mutex
+
+func sqliteRestorePath(cfg *config.Config) (string, error) {
+	if cfg == nil || strings.TrimSpace(cfg.Database.DBPath) == "" || cfg.Database.DBPath == ":memory:" || strings.HasPrefix(cfg.Database.DBPath, "file:") {
+		return "", errors.New("恢复需要配置有效的 SQLite 数据库文件路径")
+	}
+	return filepath.Abs(cfg.Database.DBPath)
+}
+
+func sqliteRestoreDSN(path, mode string) string {
+	u := url.URL{Scheme: "file", Path: filepath.ToSlash(path)}
+	q := url.Values{"mode": {mode}, "_pragma": {"busy_timeout(5000)"}}
+	u.RawQuery = q.Encode()
+	return u.String()
+}
+
+func validateSQLiteRestore(ctx context.Context, path string) error {
+	info, err := os.Lstat(path)
+	if err != nil {
+		return err
+	}
+	if !info.Mode().IsRegular() {
+		return errors.New("备份必须是常规文件")
+	}
+	db, err := sql.Open("sqlite", sqliteRestoreDSN(path, "ro"))
+	if err != nil {
+		return err
+	}
+	defer db.Close()
+	var result string
+	if err := db.QueryRowContext(ctx, "PRAGMA quick_check").Scan(&result); err != nil {
+		return fmt.Errorf("SQLite 备份校验失败: %w", err)
+	}
+	if result != "ok" {
+		return fmt.Errorf("SQLite 备份校验失败: %s", result)
+	}
+	var tables int
+	if err := db.QueryRowContext(ctx, "SELECT COUNT(*) FROM sqlite_master WHERE type = 'table' AND name IN ('users', 'media', 'settings')").Scan(&tables); err != nil {
+		return err
+	}
+	if tables == 0 {
+		return errors.New("备份不包含 MeBox 数据表")
+	}
+	return nil
+}
+
+// StageSQLiteRestore leaves the live database and its WAL untouched. The
+// validated copy is applied on the next startup, before any database is opened.
+func StageSQLiteRestore(ctx context.Context, cfg *config.Config, source string) error {
+	sqliteRestoreMu.Lock()
+	defer sqliteRestoreMu.Unlock()
+	dbPath, err := sqliteRestorePath(cfg)
+	if err != nil {
+		return err
+	}
+	pending := dbPath + ".restore-pending"
+	if _, err := os.Lstat(pending); err == nil {
+		return errors.New("已有等待恢复的备份，请重启 MeBox 后再操作")
+	} else if !errors.Is(err, os.ErrNotExist) {
+		return err
+	}
+	if err := validateSQLiteRestore(ctx, source); err != nil {
+		return err
+	}
+	in, err := os.Open(source)
+	if err != nil {
+		return err
+	}
+	defer in.Close()
+	out, err := os.CreateTemp(filepath.Dir(dbPath), ".mebox-restore-*")
+	if err != nil {
+		return err
+	}
+	tmp := out.Name()
+	defer os.Remove(tmp)
+	if _, err := io.Copy(out, in); err != nil {
+		_ = out.Close()
+		return err
+	}
+	if err := out.Sync(); err != nil {
+		_ = out.Close()
+		return err
+	}
+	if err := out.Close(); err != nil {
+		return err
+	}
+	if err := validateSQLiteRestore(ctx, tmp); err != nil {
+		return err
+	}
+	return os.Rename(tmp, pending)
+}
+
+// ApplyPendingSQLiteRestore must run before database.Open and before workers or
+// HTTP listeners start. The previous database is retained alongside the file.
+func ApplyPendingSQLiteRestore(ctx context.Context, cfg *config.Config, log *zap.Logger) error {
+	if cfg == nil {
+		return nil
+	}
+	dialect := normalizeDatabaseType(cfg.Database.Type)
+	if dialect == "auto" {
+		dialect = effectiveAutoDatabaseType(cfg)
+	}
+	if dialect != "sqlite" {
+		return nil
+	}
+	sqliteRestoreMu.Lock()
+	defer sqliteRestoreMu.Unlock()
+	dbPath, err := sqliteRestorePath(cfg)
+	if err != nil {
+		return err
+	}
+	pending := dbPath + ".restore-pending"
+	if _, err := os.Lstat(pending); errors.Is(err, os.ErrNotExist) {
+		return nil
+	} else if err != nil {
+		return err
+	}
+	if err := validateSQLiteRestore(ctx, pending); err != nil {
+		return err
+	}
+	previous := ""
+	if _, err := os.Lstat(dbPath); err == nil {
+		// A clean checkpoint prevents an old WAL from being replayed into the
+		// replacement database. A busy checkpoint leaves all files untouched.
+		live, err := sql.Open("sqlite", sqliteRestoreDSN(dbPath, "rw"))
+		if err != nil {
+			return err
+		}
+		var busy, pages, copied int
+		err = live.QueryRowContext(ctx, "PRAGMA wal_checkpoint(TRUNCATE)").Scan(&busy, &pages, &copied)
+		closeErr := live.Close()
+		if err != nil {
+			return err
+		}
+		if closeErr != nil {
+			return closeErr
+		}
+		if busy != 0 {
+			return errors.New("SQLite 数据库仍被占用，恢复已保留等待下次启动")
+		}
+		old, err := os.CreateTemp(filepath.Dir(dbPath), filepath.Base(dbPath)+".before-restore-*")
+		if err != nil {
+			return err
+		}
+		previous = old.Name()
+		if err := old.Close(); err != nil {
+			return err
+		}
+		if err := os.Remove(previous); err != nil {
+			return err
+		}
+		if err := os.Rename(dbPath, previous); err != nil {
+			return err
+		}
+	} else if !errors.Is(err, os.ErrNotExist) {
+		return err
+	}
+	if err := os.Rename(pending, dbPath); err != nil {
+		if previous != "" {
+			if rollbackErr := os.Rename(previous, dbPath); rollbackErr != nil {
+				return fmt.Errorf("恢复失败: %w；回退失败: %v，原数据库保留于 %s", err, rollbackErr, previous)
+			}
+		}
+		return err
+	}
+	if log != nil {
+		log.Warn("SQLite backup restored before startup", zap.String("previous_database", previous))
+	}
+	return nil
+}

internal/database/sqlite_restore_test.go

@@ -0,0 +1,104 @@
+package database
+
+import (
+	"database/sql"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/truewhile/MeBox/internal/config"
+)
+
+func TestSQLiteRestoreStagesWithoutChangingLiveDatabase(t *testing.T) {
+	root := t.TempDir()
+	cfg := &config.Config{}
+	cfg.Database.Type = "sqlite"
+	cfg.Database.DBPath = filepath.Join(root, "live.db")
+	live, err := sql.Open("sqlite", sqliteRestoreDSN(cfg.Database.DBPath, "rwc"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer live.Close()
+	for _, statement := range []string{
+		"PRAGMA journal_mode=WAL", "CREATE TABLE settings (key TEXT PRIMARY KEY, value TEXT)",
+		"INSERT INTO settings VALUES ('state', 'backup')",
+	} {
+		if _, err := live.Exec(statement); err != nil {
+			t.Fatal(err)
+		}
+	}
+	source := filepath.Join(root, "backup.db")
+	if _, err := live.Exec("VACUUM INTO ?", source); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := live.Exec("UPDATE settings SET value = 'live'"); err != nil {
+		t.Fatal(err)
+	}
+	if err := StageSQLiteRestore(t.Context(), cfg, source); err != nil {
+		t.Fatal(err)
+	}
+	var value string
+	if err := live.QueryRow("SELECT value FROM settings").Scan(&value); err != nil || value != "live" {
+		t.Fatalf("staging changed live database: value=%q err=%v", value, err)
+	}
+	if _, err := live.Exec("UPDATE settings SET value = 'after-stage'"); err != nil {
+		t.Fatalf("database could not write after staging: %v", err)
+	}
+	if err := StageSQLiteRestore(t.Context(), cfg, source); err == nil {
+		t.Fatal("second staging should not replace the pending restore")
+	}
+	if err := os.Remove(source); err != nil {
+		t.Fatal(err)
+	}
+	if err := live.Close(); err != nil {
+		t.Fatal(err)
+	}
+	if err := ApplyPendingSQLiteRestore(t.Context(), cfg, nil); err != nil {
+		t.Fatal(err)
+	}
+	restored, err := sql.Open("sqlite", sqliteRestoreDSN(cfg.Database.DBPath, "ro"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer restored.Close()
+	if err := restored.QueryRow("SELECT value FROM settings").Scan(&value); err != nil || value != "backup" {
+		t.Fatalf("restore failed: value=%q err=%v", value, err)
+	}
+	previous, err := filepath.Glob(cfg.Database.DBPath + ".before-restore-*")
+	if err != nil || len(previous) != 1 {
+		t.Fatalf("previous database not preserved: files=%v err=%v", previous, err)
+	}
+	old, err := sql.Open("sqlite", sqliteRestoreDSN(previous[0], "ro"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer old.Close()
+	if err := old.QueryRow("SELECT value FROM settings").Scan(&value); err != nil || value != "after-stage" {
+		t.Fatalf("old database lost latest writes: value=%q err=%v", value, err)
+	}
+	if err := ApplyPendingSQLiteRestore(t.Context(), cfg, nil); err != nil {
+		t.Fatalf("repeat startup: %v", err)
+	}
+}
+
+func TestSQLiteRestoreRejectsCorruptAndSymlinkBackups(t *testing.T) {
+	root := t.TempDir()
+	cfg := &config.Config{}
+	cfg.Database.DBPath = filepath.Join(root, "live.db")
+	source := filepath.Join(root, "corrupt.db")
+	if err := os.WriteFile(source, []byte("not a SQLite database"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	if err := StageSQLiteRestore(t.Context(), cfg, source); err == nil {
+		t.Fatal("corrupt backup accepted")
+	}
+	link := filepath.Join(root, "link.db")
+	if err := os.Symlink(source, link); err == nil {
+		if err := StageSQLiteRestore(t.Context(), cfg, link); err == nil {
+			t.Fatal("symlink backup accepted")
+		}
+	}
+	if _, err := os.Stat(cfg.Database.DBPath + ".restore-pending"); !os.IsNotExist(err) {
+		t.Fatalf("failed validation left pending data: %v", err)
+	}
+}

internal/handler/background_tasks.go

@@ -0,0 +1,18 @@
+package handler
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	"github.com/truewhile/MeBox/internal/service"
+)
+
+func backgroundTasksHandler(svc *service.Container) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		if svc == nil || svc.Tasks == nil {
+			c.JSON(http.StatusOK, service.TaskSnapshot{Active: []service.BackgroundTask{}, Recent: []service.BackgroundTask{}})
+			return
+		}
+		c.JSON(http.StatusOK, svc.Tasks.Snapshot())
+	}
+}

internal/handler/backup.go

@@ -3,6 +3,7 @@ package handler
 
 import (
 	"net/http"
+	"path/filepath"
 
 	"github.com/gin-gonic/gin"
 
@@ -41,12 +42,28 @@ func deleteBackupHandler(svc *service.Container) gin.HandlerFunc {
 	}
 }
 
+func downloadBackupHandler(svc *service.Container) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		filename := c.Query("filename")
+		path, err := svc.Backup.ResolvePath(filename)
+		if err != nil {
+			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+			return
+		}
+		c.FileAttachment(path, filepath.Base(path))
+	}
+}
+
 func restoreBackupHandler(svc *service.Container) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		if err := svc.Backup.Restore(c.Request.Context(), c.Query("filename")); err != nil {
 			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
 			return
 		}
-		c.JSON(http.StatusOK, gin.H{"message": "restored — restart the server to apply"})
+		message := "数据库已恢复，请重启 MeBox 以刷新运行时配置"
+		if svc.Repo.DB.Dialector.Name() == "sqlite" {
+			message = "备份已校验并暂存，请重启 MeBox 后应用恢复"
+		}
+		c.JSON(http.StatusOK, gin.H{"message": message, "restart_required": true})
 	}
 }

internal/handler/cloud115_playback.go

@@ -124,10 +124,32 @@ func cloud115HLSSessionHandler(svc *service.Container) gin.HandlerFunc {
 			c.JSON(http.StatusBadRequest, gin.H{"error": "missing media_id"})
 			return
 		}
-		if !enforceScopedPlaybackToken(c, mediaID) {
+		if c.Request.Context().Err() != nil {
+			c.AbortWithStatus(499)
 			return
 		}
-		err := svc.Cloud115.HLSProxy().ServeChild(
+		actualMediaID, err := svc.Cloud115.HLSProxy().SessionMediaID(c.Param("session"), c.Param("key"))
+		if err != nil {
+			c.JSON(http.StatusNotFound, gin.H{"code": "hls_session_not_found", "error": "hls session not found"})
+			return
+		}
+		if mediaID != actualMediaID {
+			c.JSON(http.StatusForbidden, gin.H{"error": "playback session media mismatch"})
+			return
+		}
+		if !enforceScopedPlaybackToken(c, actualMediaID) {
+			return
+		}
+		if svc.Repo == nil || svc.Repo.Media == nil {
+			c.JSON(http.StatusNotFound, gin.H{"error": "media not found"})
+			return
+		}
+		m, findErr := svc.Repo.Media.FindByID(c.Request.Context(), actualMediaID)
+		if findErr != nil || m == nil || !mediaVisibleForRequest(c, svc, m) {
+			c.JSON(http.StatusNotFound, gin.H{"error": "media not found"})
+			return
+		}
+		err = svc.Cloud115.HLSProxy().ServeChild(
 			c.Request.Context(),
 			c.Writer,
 			c.Request,

internal/handler/emby_playback.go

@@ -418,7 +418,11 @@ func embyVideoHLSPlaylistHandler(svc *service.Container) gin.HandlerFunc {
 			c.Status(http.StatusNotFound)
 			return
 		}
-		err = svc.Stream.ServeHLSPlaylist(c.Writer, c.Request, c.Param("id"))
+		scope, ok := localHLSPlaybackScope(c)
+		if !ok {
+			return
+		}
+		err = svc.Stream.ServeHLSPlaylist(c.Writer, c.Request, c.Param("id"), scope)
 		if errors.Is(err, service.ErrTranscodeDisabled) {
 			c.JSON(http.StatusConflict, gin.H{"error": "transcode disabled"})
 			return
@@ -444,7 +448,11 @@ func embyVideoHLSSegmentHandler(svc *service.Container) gin.HandlerFunc {
 			c.Status(http.StatusNotFound)
 			return
 		}
-		if err := svc.Stream.ServeHLSSegment(c.Writer, c.Request, c.Param("id"), c.Param("seg")); err != nil {
+		scope, ok := localHLSPlaybackScope(c)
+		if !ok {
+			return
+		}
+		if err := svc.Stream.ServeHLSSegment(c.Writer, c.Request, c.Param("id"), c.Param("seg"), scope); err != nil {
 			c.Status(http.StatusNotFound)
 		}
 	}

internal/handler/hls_session_test.go

@@ -0,0 +1,37 @@
+package handler
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"go.uber.org/zap"
+
+	"github.com/truewhile/MeBox/internal/middleware"
+	"github.com/truewhile/MeBox/internal/model"
+	"github.com/truewhile/MeBox/internal/service"
+)
+
+func TestStopHLSChecksMediaVisibility(t *testing.T) {
+	router, svc, secret := newPlaybackScopeTestRouter(t)
+	svc.Transcoder = service.NewTranscoderService(svc.Cfg, zap.NewNop(), svc.Repo, nil)
+	router.DELETE("/api/hls/:id", middleware.AuthRequired(secret), stopTranscodeHandler(svc))
+	req := httptest.NewRequest(http.MethodDelete, "/api/hls/nonexistent?session_id=player-a", nil)
+	req.Header.Set("Authorization", "Bearer "+signedTestToken(t, secret))
+	rec := httptest.NewRecorder()
+	router.ServeHTTP(rec, req)
+	if rec.Code != http.StatusNotFound {
+		t.Fatalf("stop of a nonexistent/invisible media: status=%d body=%s, want 404", rec.Code, rec.Body.String())
+	}
+	profile := &model.PlayProfile{UserID: "user-1", Name: "restricted", IsDefault: true, AllowedLibraryIDs: `["other-library"]`}
+	if err := svc.Repo.DB.Create(profile).Error; err != nil {
+		t.Fatal(err)
+	}
+	req = httptest.NewRequest(http.MethodDelete, "/api/hls/media-1?session_id=player-a", nil)
+	req.Header.Set("Authorization", "Bearer "+signedTestToken(t, secret))
+	rec = httptest.NewRecorder()
+	router.ServeHTTP(rec, req)
+	if rec.Code != http.StatusNotFound {
+		t.Fatalf("invisible existing media can be stopped: %d %s", rec.Code, rec.Body.String())
+	}
+}

internal/handler/media.go

@@ -4,8 +4,10 @@ package handler
 import (
 	"context"
 	"errors"
+	"fmt"
 	"math"
 	"net/http"
+	"sort"
 	"strconv"
 	"strings"
 	"sync"
@@ -40,6 +42,11 @@ type webLibraryPayload struct {
 	Cards        []service.SeriesCardView `json:"cards,omitempty"`
 }
 
+// remoteLibraryPreviewBudget 限制 /api/libraries?with_preview=1 里远程 Emby
+// 库预览（总条数 + 最新卡片）的总耗时。这些预览只用于首页卡片，值得为它
+// 排队等待的量很小；此前它跟随请求上下文，上游超时会让整页等 15 秒以上。
+var remoteLibraryPreviewBudget = 3 * time.Second
+
 // remoteLibraryItemTypes 远程库内容拉取时按 CollectionType 过滤直属条目，
 // 避免电影库里的合集文件夹(Folder) 漏出为电影卡片。
 func remoteLibraryItemTypes(collectionType string) string {
@@ -176,6 +183,12 @@ func listLibrariesHandler(svc *service.Container) gin.HandlerFunc {
 					remotePayloads[i] = webLibraryPayload{Library: v.Library, IsRemoteEmby: true, RemoteSource: v.AccountName}
 				}
 				if withPreview && len(allowedViews) > 0 {
+					// 远程库预览只是首页卡片上的「最新几条」，绝不能拖住整个
+					// 库列表：上游 Emby 一旦超时，每个远程库都要等满
+					// embyRemoteHTTPTimeout（15s），串起来就是 17–30 秒。
+					// 给整段预览一个总预算，超时就只返回库名，卡片留给下一次刷新。
+					previewCtx, cancelPreview := context.WithTimeout(ctx, remoteLibraryPreviewBudget)
+					defer cancelPreview()
 					const maxRemotePreviewWorkers = 6
 					sem := make(chan struct{}, maxRemotePreviewWorkers)
 					var wg sync.WaitGroup
@@ -187,11 +200,11 @@ func listLibrariesHandler(svc *service.Container) gin.HandlerFunc {
 							select {
 							case sem <- struct{}{}:
 								defer func() { <-sem }()
-							case <-ctx.Done():
+							case <-previewCtx.Done():
 								return
 							}
 							helper.Run(svc.Log, "media.remotePreview", func() {
-								acct := svc.EmbyRemote.AccountByID(ctx, v.AccountID)
+								acct := svc.EmbyRemote.AccountByID(previewCtx, v.AccountID)
 								if acct == nil {
 									return
 								}
@@ -203,10 +216,10 @@ func listLibrariesHandler(svc *service.Container) gin.HandlerFunc {
 									Name:           v.Library.Name,
 								}
 								itemTypes := remoteLibraryItemTypes(v.CollectionType)
-								if _, total, err := svc.EmbyRemote.RemoteLibraryMedia(ctx, tmpMount, acct, v.RemoteID, itemTypes, 0, 1); err == nil {
+								if _, total, err := svc.EmbyRemote.RemoteLibraryMedia(previewCtx, tmpMount, acct, v.RemoteID, itemTypes, 0, 1); err == nil {
 									remotePayloads[i].Total = total
 								}
-								if cards, err := svc.EmbyRemote.RemoteLatestCards(ctx, tmpMount, acct, v.RemoteID, limit); err == nil {
+								if cards, err := svc.EmbyRemote.RemoteLatestCards(previewCtx, tmpMount, acct, v.RemoteID, limit); err == nil {
 									remotePayloads[i].Cards = service.NewSeriesCardViews(cards)
 								}
 							})
@@ -556,19 +569,17 @@ func listMediaHandler(svc *service.Container) gin.HandlerFunc {
 			})
 			return
 		}
-		grouped, err := svc.Media.GroupedMediaVisibleFiltered(ctx, id, mediaVisibilityForRequest(c, svc), filters)
+		items, total, err := svc.Media.ListMediaVisibleSortedPage(ctx, id, page, size, mediaVisibilityForRequest(c, svc), filters, sortSpec, history)
 		if err != nil {
 			writeInternalOrCanceled(c, err)
 			return
 		}
-		grouped = service.SortMediaItems(grouped, sortSpec.Field, sortSpec.Order, history)
-		items := service.PaginateMediaItems(grouped, page, size)
 		if items == nil {
 			items = []service.MediaItem{}
 		}
 		c.JSON(http.StatusOK, gin.H{
 			"items":     items,
-			"total":     len(grouped),
+			"total":     total,
 			"page":      page,
 			"page_size": size,
 		})
@@ -656,6 +667,9 @@ func paginateSlice[T any](items []T, page, size int) []T {
 	if len(items) == 0 {
 		return []T{}
 	}
+	if page-1 > len(items)/size {
+		return []T{}
+	}
 	start := (page - 1) * size
 	if start >= len(items) {
 		return []T{}
@@ -670,127 +684,257 @@ func paginateSlice[T any](items []T, page, size int) []T {
 func searchMediaHandler(svc *service.Container) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		ctx := c.Request.Context()
-		q := c.Query("q")
+		query := strings.TrimSpace(c.Query("q"))
 		visibility := mediaVisibilityForRequest(c, svc)
-		groupVersions := c.DefaultQuery("group_versions", "1") != "0"
-
-		fetchRemote := func(limit int) []model.Media {
-			if svc.EmbyRemote == nil || strings.TrimSpace(q) == "" {
-				return nil
-			}
-			remoteItems, _ := svc.EmbyRemote.RemoteSearchMedia(ctx, q, limit, visibility)
-			return remoteItems
+		filter := service.MediaSearchFilter{
+			LibraryID: strings.TrimSpace(c.Query("library_id")),
+			YearMin:   boundedSearchYear(c.Query("year_min")),
+			YearMax:   boundedSearchYear(c.Query("year_max")),
 		}
-
-		if c.DefaultQuery("group_series", "0") != "0" {
-			localItems, err := svc.Media.SearchMediaVisible(ctx, q, 50000, visibility)
-			if err != nil {
-				c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
-				return
+		for _, genre := range c.QueryArray("genre") {
+			if genre = strings.TrimSpace(genre); genre != "" && len(filter.Genres) < 8 {
+				filter.Genres = append(filter.Genres, genre)
 			}
-			remoteItems := fetchRemote(50000)
-			all := service.GroupMediaSeriesItems(append(localItems, remoteItems...))
-
-			if c.Query("page") != "" || c.Query("page_size") != "" {
-				page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
-				size, _ := strconv.Atoi(c.DefaultQuery("page_size", "50"))
-				paged := paginateSlice(all, page, size)
-				c.JSON(http.StatusOK, gin.H{
-					"items":     paged,
-					"total":     len(all),
-					"page":      page,
-					"page_size": size,
-				})
-				return
-			}
-
-			limit, _ := strconv.Atoi(c.DefaultQuery("limit", "50"))
-			if limit <= 0 {
-				limit = 50
-			}
-			if len(all) > limit {
-				all = all[:limit]
-			}
-			c.JSON(http.StatusOK, gin.H{"items": all})
-			return
 		}
-
-		if c.Query("page") != "" || c.Query("page_size") != "" {
-			page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
-			size, _ := strconv.Atoi(c.DefaultQuery("page_size", "50"))
-			if !groupVersions {
-				localItems, _, err := svc.Media.SearchMediaVisiblePage(ctx, q, 1, 50000, visibility)
-				if err != nil {
-					c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
-					return
-				}
-				remoteItems := fetchRemote(size * 2)
-				all := append(localItems, remoteItems...)
-				paged := paginateSlice(all, page, size)
-				c.JSON(http.StatusOK, gin.H{
-					"items":     paged,
-					"total":     len(all),
-					"page":      page,
-					"page_size": size,
-				})
-				return
-			}
-			localItems, err := svc.Media.SearchMediaVisible(ctx, q, 50000, visibility)
-			if err != nil {
-				c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
-				return
-			}
-			remoteItems := fetchRemote(size * 2)
-			all := append(localItems, remoteItems...)
-			grouped := service.GroupMediaVersions(all)
-			paged := service.PaginateMediaItems(grouped, page, size)
-			c.JSON(http.StatusOK, gin.H{
-				"items":     paged,
-				"total":     len(grouped),
-				"page":      page,
-				"page_size": size,
-			})
-			return
+		if filter.YearMin > 0 && filter.YearMax > 0 && filter.YearMin > filter.YearMax {
+			filter.YearMin, filter.YearMax = filter.YearMax, filter.YearMin
+		}
+		page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+		if page < 1 {
+			page = 1
+		}
+		size, _ := strconv.Atoi(c.DefaultQuery("page_size", "50"))
+		if size < 1 {
+			size = 50
+		} else if size > 2000 {
+			size = 2000
 		}
-
 		limit, _ := strconv.Atoi(c.DefaultQuery("limit", "50"))
-		if limit <= 0 {
+		if limit < 1 {
 			limit = 50
+		} else if limit > 50000 {
+			limit = 50000
 		}
-		if !groupVersions {
-			localItems, err := svc.Media.SearchMediaVisible(ctx, q, limit, visibility)
-			if err != nil {
-				c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
-				return
-			}
-			remoteItems := fetchRemote(limit)
-			all := append(localItems, remoteItems...)
-			if len(all) > limit {
-				all = all[:limit]
-			}
-			if all == nil {
-				all = []model.Media{}
-			}
-			c.JSON(http.StatusOK, gin.H{"items": all})
-			return
-		}
-
-		localItems, err := svc.Media.SearchMediaVisible(ctx, q, 50000, visibility)
+		paginated := c.Query("page") != "" || c.Query("page_size") != ""
+		sortBy := normalizeMediaSearchSort(c.Query("sort"))
+		// 远程搜索与本地查询并行发起：本地结果不再排在远程超时之后才返回。
+		remoteCh := startRemoteMediaSearch(ctx, svc, query, visibility, filter)
+		// Sorting and grouping must operate on the same candidate set before
+		// either a page size or the caller's output limit is applied.
+		items, err := svc.Media.SearchMediaVisibleFiltered(ctx, query, 50000, visibility, filter)
 		if err != nil {
 			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
 			return
 		}
-		remoteItems := fetchRemote(limit)
-		all := append(localItems, remoteItems...)
-		grouped := service.GroupMediaVersions(all)
-		items := service.FirstMediaItems(grouped, limit)
-		if items == nil {
-			items = []service.MediaItem{}
+		if remoteCh != nil {
+			for _, item := range <-remoteCh {
+				items = append(items, item)
+			}
 		}
-		c.JSON(http.StatusOK, gin.H{"items": items})
+		if c.DefaultQuery("group_series", "0") != "0" {
+			items = service.GroupMediaSeriesItems(items)
+			sortSearchMedia(items, sortBy)
+			writeMediaSearchResults(c, items, page, size, limit, paginated)
+			return
+		}
+		if c.DefaultQuery("group_versions", "1") != "0" {
+			grouped := service.GroupMediaVersions(items)
+			if sortBy != "" {
+				sort.SliceStable(grouped, func(i, j int) bool {
+					return mediaSearchSortLess(grouped[i].Media, grouped[j].Media, sortBy)
+				})
+			}
+			writeMediaSearchResults(c, grouped, page, size, limit, paginated)
+			return
+		}
+		sortSearchMedia(items, sortBy)
+		writeMediaSearchResults(c, items, page, size, limit, paginated)
 	}
 }
 
+const (
+	// remoteSearchItemLimit 是每个远程 Emby 挂载点返回的条目上限。此前这里传
+	// 50000（等于让上游做一次全库查询），上游稍慢就会一路跑到 5 秒超时，把每次
+	// 搜索都拖成秒级；搜索场景只需要少量候选，多出来的结果也会被分页丢掉。
+	remoteSearchItemLimit = 100
+	// remoteSearchBudget 限制远程结果最多给一次请求增加多少延迟。
+	remoteSearchBudget = 2 * time.Second
+	// remoteSearchCacheTTL 让同一关键词的翻页与重复搜索复用远程结果，避免每翻
+	// 一页都重新打一遍远程挂载点。
+	remoteSearchCacheTTL = 30 * time.Second
+	// remoteSearchFailureCacheTTL 用于上游超时/失败时的短缓存：部分结果只保留
+	// 几秒，避免反复吃满 remoteSearchBudget，又不至于长期压住后续重试。
+	remoteSearchFailureCacheTTL = 5 * time.Second
+)
+
+// startRemoteMediaSearch 并发发起远程搜索，返回一个只投递一次结果的通道。
+// 不满足远程搜索条件时返回 nil。通道带缓冲，调用方即使提前返回也不会泄漏
+// goroutine；请求结束时请求上下文被取消，远程调用会随之退出。
+func startRemoteMediaSearch(
+	ctx context.Context,
+	svc *service.Container,
+	query string,
+	visibility service.MediaVisibility,
+	filter service.MediaSearchFilter,
+) <-chan []model.Media {
+	if svc == nil || svc.EmbyRemote == nil || query == "" {
+		return nil
+	}
+	if filter.LibraryID != "" && !service.IsEmbyRemoteID(filter.LibraryID) {
+		return nil
+	}
+	results := make(chan []model.Media, 1)
+	go func() {
+		results <- remoteMediaSearchItems(ctx, svc, query, visibility, filter)
+	}()
+	return results
+}
+
+func remoteMediaSearchItems(
+	ctx context.Context,
+	svc *service.Container,
+	query string,
+	visibility service.MediaVisibility,
+	filter service.MediaSearchFilter,
+) []model.Media {
+	cacheKey := remoteSearchCacheKey(query, visibility)
+	if svc.Cache != nil {
+		if cached, ok := svc.Cache.GetObject(cacheKey); ok {
+			if rows, ok := cached.([]model.Media); ok {
+				return filterRemoteSearchItems(rows, filter)
+			}
+		}
+	}
+	searchCtx, cancel := context.WithTimeout(ctx, remoteSearchBudget)
+	defer cancel()
+	remote, _ := svc.EmbyRemote.RemoteSearchMedia(searchCtx, query, remoteSearchItemLimit, visibility)
+	if svc.Cache != nil {
+		// 空结果也要缓存：否则查不到片名时每次都会重新等到 remoteSearchBudget。
+		if remote == nil {
+			remote = []model.Media{}
+		}
+		ttl := remoteSearchCacheTTL
+		if searchCtx.Err() != nil {
+			ttl = remoteSearchFailureCacheTTL
+		}
+		svc.Cache.SetObject(cacheKey, remote, ttl)
+	}
+	return filterRemoteSearchItems(remote, filter)
+}
+
+func filterRemoteSearchItems(remote []model.Media, filter service.MediaSearchFilter) []model.Media {
+	if len(remote) == 0 {
+		return nil
+	}
+	out := make([]model.Media, 0, len(remote))
+	for _, item := range remote {
+		if remoteSearchMatchesFilter(item, filter) {
+			out = append(out, item)
+		}
+	}
+	return out
+}
+
+// remoteSearchCacheKey 按可见范围隔离远程搜索结果，避免把某个用户可见挂载
+// 点的结果复用给可见范围不同的用户。
+func remoteSearchCacheKey(query string, visibility service.MediaVisibility) string {
+	allowed := append([]string(nil), visibility.AllowedLibraryIDs...)
+	hidden := append([]string(nil), visibility.HiddenLibraryIDs...)
+	sort.Strings(allowed)
+	sort.Strings(hidden)
+	return fmt.Sprintf("media:obj:remote-search:%t|%s|%s|%s",
+		visibility.IncludeNSFW, strings.Join(allowed, ","), strings.Join(hidden, ","), query)
+}
+
+func writeMediaSearchResults[T any](c *gin.Context, items []T, page, size, limit int, paginated bool) {
+	if items == nil {
+		items = []T{}
+	}
+	if paginated {
+		c.JSON(http.StatusOK, gin.H{
+			"items": paginateSlice(items, page, size),
+			"total": len(items), "page": page, "page_size": size,
+		})
+		return
+	}
+	if len(items) > limit {
+		items = items[:limit]
+	}
+	c.JSON(http.StatusOK, gin.H{"items": items})
+}
+
+func remoteSearchMatchesFilter(item model.Media, filter service.MediaSearchFilter) bool {
+	if filter.LibraryID != "" && item.LibraryID != filter.LibraryID && item.DisplayLibraryID != filter.LibraryID {
+		return false
+	}
+	if filter.YearMin > 0 && item.Year < filter.YearMin || filter.YearMax > 0 && item.Year > filter.YearMax {
+		return false
+	}
+	if len(filter.Genres) == 0 {
+		return true
+	}
+	normalize := func(value string) string {
+		return strings.ToLower(strings.ReplaceAll(strings.TrimSpace(value), " ", ""))
+	}
+	for _, genre := range strings.Split(strings.ReplaceAll(item.Genres, "，", ","), ",") {
+		for _, wanted := range filter.Genres {
+			if normalize(genre) == normalize(wanted) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func normalizeMediaSearchSort(value string) string {
+	value = strings.TrimSpace(value)
+	switch value {
+	case "title_asc", "year_desc", "rating_desc":
+		return value
+	default:
+		return ""
+	}
+}
+
+func sortSearchMedia(items []model.Media, sortBy string) {
+	if sortBy == "" {
+		return
+	}
+	sort.SliceStable(items, func(i, j int) bool {
+		return mediaSearchSortLess(items[i], items[j], sortBy)
+	})
+}
+
+func mediaSearchSortLess(a, b model.Media, sortBy string) bool {
+	switch sortBy {
+	case "title_asc":
+		left, right := strings.ToLower(strings.TrimSpace(a.Title)), strings.ToLower(strings.TrimSpace(b.Title))
+		if left != right {
+			return left < right
+		}
+	case "year_desc":
+		if a.Year != b.Year {
+			return a.Year > b.Year
+		}
+	case "rating_desc":
+		if a.Rating != b.Rating {
+			return a.Rating > b.Rating
+		}
+	}
+	if !a.CreatedAt.Equal(b.CreatedAt) {
+		return a.CreatedAt.After(b.CreatedAt)
+	}
+	return a.ID < b.ID
+}
+
+func boundedSearchYear(value string) int {
+	year, err := strconv.Atoi(strings.TrimSpace(value))
+	if err != nil || year < 1870 || year > 2200 {
+		return 0
+	}
+	return year
+}
+
 func streamHandler(svc *service.Container) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		ctx := c.Request.Context()

internal/handler/media_libraries_preview_test.go

@@ -0,0 +1,136 @@
+package handler
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"github.com/glebarez/sqlite"
+	"go.uber.org/zap"
+	"gorm.io/gorm"
+
+	"github.com/truewhile/MeBox/internal/config"
+	"github.com/truewhile/MeBox/internal/middleware"
+	"github.com/truewhile/MeBox/internal/model"
+	"github.com/truewhile/MeBox/internal/repository"
+	"github.com/truewhile/MeBox/internal/service"
+)
+
+// TestListLibrariesRemotePreviewIsBounded 锁定远程库预览的总预算：
+// 上游 Emby 卡住时，/api/libraries?with_preview=1 必须按时返回远程库条目
+// （只是没有卡片），而不是跟着上游一起等十几秒。线上实测这个接口因此出现过
+// 17.4 秒、30 秒（前端放弃）的响应，设置页也跟着整页空转。
+func TestListLibrariesRemotePreviewIsBounded(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	oldBudget := remoteLibraryPreviewBudget
+	remoteLibraryPreviewBudget = 200 * time.Millisecond
+	t.Cleanup(func() { remoteLibraryPreviewBudget = oldBudget })
+
+	// Views / 用户列表正常返回，Preview（Items 查询）永远不返回：模拟上游半挂。
+	release := make(chan struct{})
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		path := r.URL.Path
+		switch {
+		case strings.HasSuffix(path, "/Views"):
+			_ = json.NewEncoder(w).Encode(map[string]any{
+				"Items": []map[string]any{{
+					"Id": "view-1", "Name": "远程动画", "CollectionType": "tvshows",
+				}},
+			})
+			return
+		case strings.HasSuffix(path, "/Users"):
+			// api_key 账号要先解析出远程用户 Id，否则请求路径会落到兜底 "0"。
+			_ = json.NewEncoder(w).Encode([]map[string]any{{"Id": "uid-1", "Name": "admin"}})
+			return
+		case r.Method == http.MethodPost:
+			_ = json.NewEncoder(w).Encode(map[string]any{
+				"AccessToken": "fake-token",
+				"User":        map[string]any{"Id": "uid-1"},
+			})
+			return
+		}
+		select {
+		case <-release:
+		case <-r.Context().Done():
+		case <-time.After(30 * time.Second):
+		}
+		w.WriteHeader(http.StatusGatewayTimeout)
+	}))
+	defer upstream.Close()
+	defer close(release)
+
+	// 唯一库名 + cache=shared：预览协程会并发读库（账号解析）。
+	dsn := fmt.Sprintf("file:%s?mode=memory&cache=shared", strings.ReplaceAll(t.Name(), "/", "_"))
+	db, err := gorm.Open(sqlite.Open(dsn), &gorm.Config{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := db.AutoMigrate(&model.Library{}, &model.Media{}, &model.StrmAccount{}, &model.EmbyMount{}, &model.Setting{}, &model.User{}, &model.PlayProfile{}); err != nil {
+		t.Fatal(err)
+	}
+	repos := repository.New(db)
+	if err := db.Create(&model.User{Base: model.Base{ID: "admin-1"}, Username: "admin", Role: "admin"}).Error; err != nil {
+		t.Fatal(err)
+	}
+	rawConfig, _ := json.Marshal(map[string]string{"url": upstream.URL, "token": "fake-token"})
+	acct := model.StrmAccount{
+		Base: model.Base{ID: "acct-1"}, Name: "远程Emby", Provider: model.StrmProviderEmbyRemote,
+		Config: string(rawConfig), Enabled: true,
+	}
+	if err := repos.StrmAccount.Create(t.Context(), &acct); err != nil {
+		t.Fatal(err)
+	}
+	mount := model.EmbyMount{
+		Base: model.Base{ID: "mount-1"}, AccountID: acct.ID, RemoteViewID: "view-1",
+		RemoteViewName: "远程动画", CollectionType: "tvshows", Enabled: true,
+	}
+	if err := repos.EmbyMount.Create(t.Context(), &mount); err != nil {
+		t.Fatal(err)
+	}
+	svc := &service.Container{
+		Repo:       repos,
+		Media:      service.NewMediaService(&config.Config{}, zap.NewNop(), repos),
+		EmbyRemote: service.NewEmbyRemoteService(&config.Config{}, zap.NewNop(), repos, service.NewCryptoService("", zap.NewNop())),
+		Cache:      service.NewRuntimeCacheService(&config.Config{}, zap.NewNop()),
+	}
+
+	w := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(w)
+	c.Set(middleware.CtxUserID, "admin-1")
+	c.Set(middleware.CtxUserRole, "admin")
+	c.Request = httptest.NewRequest(http.MethodGet, "/api/libraries?with_preview=1&include_hidden=1", nil)
+
+	start := time.Now()
+	listLibrariesHandler(svc)(c)
+	elapsed := time.Since(start)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("status=%d body=%s", w.Code, w.Body.String())
+	}
+	if elapsed > 2*time.Second {
+		t.Fatalf("request took %v with a hung upstream; the preview budget must bound it", elapsed)
+	}
+	var payload []webLibraryPayload
+	if err := json.Unmarshal(w.Body.Bytes(), &payload); err != nil {
+		t.Fatalf("decode response: %v (%s)", err, w.Body.String())
+	}
+	var remote *webLibraryPayload
+	for i := range payload {
+		if payload[i].IsRemoteEmby {
+			remote = &payload[i]
+			break
+		}
+	}
+	if remote == nil {
+		t.Fatalf("remote library missing from the bounded response: %#v", payload)
+	}
+	if len(remote.Cards) != 0 || remote.Total != 0 {
+		t.Fatalf("expected the preview to be skipped on timeout, got total=%d cards=%d", remote.Total, len(remote.Cards))
+	}
+}

internal/handler/media_quality.go

@@ -0,0 +1,37 @@
+package handler
+
+import (
+	"net/http"
+	"strconv"
+
+	"github.com/gin-gonic/gin"
+	"github.com/truewhile/MeBox/internal/service"
+)
+
+func mediaQualityHandler(svc *service.Container) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+		pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "50"))
+		if page < 1 {
+			page = 1
+		} else if page > 1000000 {
+			page = 1000000
+		}
+		if pageSize < 1 {
+			pageSize = 50
+		} else if pageSize > 100 {
+			pageSize = 100
+		}
+		issue := c.DefaultQuery("issue", "unmatched")
+		if issue != "unmatched" && issue != "poster" && issue != "missing" {
+			c.JSON(http.StatusBadRequest, gin.H{"error": "未知检查分类"})
+			return
+		}
+		items, total, err := svc.Media.QualityIssues(c.Request.Context(), issue, page, pageSize)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+			return
+		}
+		c.JSON(http.StatusOK, gin.H{"items": items, "total": total, "page": page, "page_size": pageSize})
+	}
+}

internal/handler/media_search_filters_test.go

@@ -0,0 +1,88 @@
+package handler
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/glebarez/sqlite"
+	"go.uber.org/zap"
+	"gorm.io/gorm"
+
+	"github.com/truewhile/MeBox/internal/config"
+	"github.com/truewhile/MeBox/internal/middleware"
+	"github.com/truewhile/MeBox/internal/model"
+	"github.com/truewhile/MeBox/internal/repository"
+	"github.com/truewhile/MeBox/internal/service"
+)
+
+func TestSearchMediaSortLimitFiltersAndDeepPagination(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	sqlDB, _ := db.DB()
+	defer sqlDB.Close()
+	if err := db.AutoMigrate(&model.Library{}, &model.Media{}, &model.User{}, &model.Setting{}, &model.PlayProfile{}); err != nil {
+		t.Fatal(err)
+	}
+	repos := repository.New(db)
+	lib := model.Library{Name: "Review", Path: "/review", Type: "movie", Enabled: true}
+	if err := repos.Library.Create(t.Context(), &lib); err != nil {
+		t.Fatal(err)
+	}
+	rows := make([]model.Media, 2001)
+	for i := range rows {
+		rows[i] = model.Media{
+			Base: model.Base{ID: fmt.Sprintf("review-%04d", i)}, LibraryID: lib.ID,
+			Title: fmt.Sprintf("Review %04d", i), Path: fmt.Sprintf("/review/%04d.mp4", i), Year: 2020, Genres: "Comedy",
+		}
+	}
+	rows[2000].Year = 2025
+	rows[2000].Genres = "Drama"
+	if err := db.CreateInBatches(rows, 100).Error; err != nil {
+		t.Fatal(err)
+	}
+	svc := &service.Container{Repo: repos, Media: service.NewMediaService(&config.Config{}, zap.NewNop(), repos)}
+	cases := []struct {
+		name, query, expectedID  string
+		count, total, page, size int
+	}{
+		{name: "sorted output limit", query: "sort=year_desc&limit=1", expectedID: "review-2000", count: 1},
+		{name: "page past old 2000 cap", query: "sort=title_asc&page=2001&page_size=1", expectedID: "review-2000", count: 1, total: 2001, page: 2001, size: 1},
+		{name: "genre filtering", query: "genre=Drama&library_id=" + lib.ID, expectedID: "review-2000", count: 1},
+		{name: "normalized page", query: "page=0&page_size=0", count: 50, total: 2001, page: 1, size: 50},
+		{name: "bounded page size", query: "page=1&page_size=99999", count: 2000, total: 2001, page: 1, size: 2000},
+		{name: "huge page does not overflow", query: "page=" + strconv.Itoa(int(^uint(0)>>1)) + "&page_size=2000", count: 0, total: 2001, page: int(^uint(0) >> 1), size: 2000},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			w := httptest.NewRecorder()
+			ctx, _ := gin.CreateTestContext(w)
+			ctx.Set(middleware.CtxUserID, "admin")
+			ctx.Set(middleware.CtxUserRole, "admin")
+			ctx.Request = httptest.NewRequest(http.MethodGet, "/api/media?q=Review&group_versions=0&"+tc.query, nil)
+			searchMediaHandler(svc)(ctx)
+			var response struct {
+				Items []model.Media `json:"items"`
+				Total int           `json:"total"`
+				Page  int           `json:"page"`
+				Size  int           `json:"page_size"`
+			}
+			if w.Code != http.StatusOK || json.Unmarshal(w.Body.Bytes(), &response) != nil {
+				t.Fatalf("search failed: status=%d body=%s", w.Code, w.Body.String())
+			}
+			if len(response.Items) != tc.count || response.Total != tc.total || response.Page != tc.page || response.Size != tc.size {
+				t.Fatalf("response count=%d total=%d page=%d size=%d, want %#v", len(response.Items), response.Total, response.Page, response.Size, tc)
+			}
+			if tc.expectedID != "" && response.Items[0].ID != tc.expectedID {
+				t.Fatalf("first ID=%q want %q", response.Items[0].ID, tc.expectedID)
+			}
+		})
+	}
+}

internal/handler/media_search_remote_test.go

@@ -0,0 +1,153 @@
+package handler
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"sync"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/glebarez/sqlite"
+	"go.uber.org/zap"
+	"gorm.io/gorm"
+
+	"github.com/truewhile/MeBox/internal/config"
+	"github.com/truewhile/MeBox/internal/middleware"
+	"github.com/truewhile/MeBox/internal/model"
+	"github.com/truewhile/MeBox/internal/repository"
+	"github.com/truewhile/MeBox/internal/service"
+)
+
+// TestSearchMediaRemoteSearchBoundedAndCached 防止远程搜索再次退化：
+// 1. 每个挂载点的 Limit 必须是 remoteSearchItemLimit，而不是历史全库查询的 50000；
+// 2. 同一关键词的重复搜索应命中缓存，不再打上游；
+// 3. 指定本地媒体库时不应枚举远程挂载点。
+func TestSearchMediaRemoteSearchBoundedAndCached(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	var mu sync.Mutex
+	searchCalls := 0
+	searchLimits := make([]string, 0, 4)
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if term := r.URL.Query().Get("SearchTerm"); term != "" {
+			mu.Lock()
+			searchCalls++
+			searchLimits = append(searchLimits, r.URL.Query().Get("Limit"))
+			mu.Unlock()
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_ = json.NewEncoder(w).Encode(map[string]any{
+			"TotalRecordCount": 1,
+			"Items": []map[string]any{{
+				"Id":             "remote-1",
+				"Name":           "远方剧集",
+				"Type":           "Series",
+				"ProductionYear": 2024,
+			}},
+		})
+	}))
+	defer upstream.Close()
+
+	// 唯一库名 + cache=shared：远程搜索与本地查询会并发读库，
+	// 而 :memory: 下每个连接各自一个空库，并发连接会读到「no such table」。
+	dsn := fmt.Sprintf("file:%s?mode=memory&cache=shared", strings.ReplaceAll(t.Name(), "/", "_"))
+	db, err := gorm.Open(sqlite.Open(dsn), &gorm.Config{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := db.AutoMigrate(&model.Library{}, &model.Media{}, &model.StrmAccount{}, &model.EmbyMount{}, &model.Setting{}, &model.User{}, &model.PlayProfile{}); err != nil {
+		t.Fatal(err)
+	}
+	repos := repository.New(db)
+	if err := repos.DB.Create(&model.User{Base: model.Base{ID: "user-1"}, Username: "admin", Role: "admin"}).Error; err != nil {
+		t.Fatal(err)
+	}
+	lib := model.Library{Name: "本地电影", Path: "/media/movies", Type: "movie", Enabled: true}
+	if err := repos.Library.Create(t.Context(), &lib); err != nil {
+		t.Fatal(err)
+	}
+	if err := db.Create(&model.Media{
+		Base: model.Base{ID: "local-1"}, LibraryID: lib.ID, Title: "流浪地球", Path: "/media/movies/流浪地球.mkv",
+	}).Error; err != nil {
+		t.Fatal(err)
+	}
+	rawConfig, _ := json.Marshal(map[string]string{"url": upstream.URL, "token": "fake-token"})
+	acct := model.StrmAccount{
+		Base: model.Base{ID: "acct"}, Name: "远程Emby", Provider: model.StrmProviderEmbyRemote,
+		Config: string(rawConfig), Enabled: true,
+	}
+	if err := repos.StrmAccount.Create(t.Context(), &acct); err != nil {
+		t.Fatal(err)
+	}
+	mount := model.EmbyMount{
+		Base: model.Base{ID: "mount-1"}, AccountID: acct.ID, RemoteViewID: "view-1",
+		RemoteViewName: "远程剧集", CollectionType: "tvshows", Enabled: true,
+	}
+	if err := repos.EmbyMount.Create(t.Context(), &mount); err != nil {
+		t.Fatal(err)
+	}
+
+	svc := &service.Container{
+		Repo:       repos,
+		Media:      service.NewMediaService(&config.Config{}, zap.NewNop(), repos),
+		EmbyRemote: service.NewEmbyRemoteService(&config.Config{}, zap.NewNop(), repos, service.NewCryptoService("", zap.NewNop())),
+		Cache:      service.NewRuntimeCacheService(&config.Config{}, zap.NewNop()),
+	}
+
+	search := func(params string) []service.MediaItem {
+		t.Helper()
+		w := httptest.NewRecorder()
+		c, _ := gin.CreateTestContext(w)
+		c.Set(middleware.CtxUserID, "user-1")
+		c.Set(middleware.CtxUserRole, "admin")
+		c.Request = httptest.NewRequest(http.MethodGet, "/api/media?"+params, nil)
+		searchMediaHandler(svc)(c)
+		if w.Code != http.StatusOK {
+			t.Fatalf("search status=%d, body=%s", w.Code, w.Body.String())
+		}
+		var response struct {
+			Items []service.MediaItem `json:"items"`
+		}
+		if err := json.Unmarshal(w.Body.Bytes(), &response); err != nil {
+			t.Fatal(err)
+		}
+		return response.Items
+	}
+	callCount := func() int {
+		mu.Lock()
+		defer mu.Unlock()
+		return searchCalls
+	}
+
+	if items := search("q=远方&page=1&page_size=48"); len(items) != 1 || items[0].Title != "远方剧集" {
+		t.Fatalf("expected remote result, got %#v", items)
+	}
+	if calls := callCount(); calls != 1 {
+		t.Fatalf("expected exactly one upstream search, got %d", calls)
+	}
+	mu.Lock()
+	limit := searchLimits[0]
+	mu.Unlock()
+	if limit != "100" {
+		t.Fatalf("remote search Limit=%q, want bounded 100 (50000 means a full-library query)", limit)
+	}
+
+	// 同一关键词再来一次（例如刷新/重复搜索）应复用缓存，不再请求上游。
+	if items := search("q=远方&page=1&page_size=48"); len(items) != 1 || items[0].Title != "远方剧集" {
+		t.Fatalf("cached search lost the remote result: %#v", items)
+	}
+	if calls := callCount(); calls != 1 {
+		t.Fatalf("expected cached remote search to skip upstream, got %d calls", calls)
+	}
+
+	// 指定本地媒体库时不应枚举远程挂载点。
+	if items := search("q=流浪&page=1&page_size=48&library_id=" + lib.ID); len(items) != 1 || items[0].ID != "local-1" {
+		t.Fatalf("expected local-only result, got %#v", items)
+	}
+	if calls := callCount(); calls != 1 {
+		t.Fatalf("local library filter must not hit upstream, got %d calls", calls)
+	}
+}

internal/handler/media_search_test.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"net/http"
 	"net/http/httptest"
+	"net/url"
+	"strings"
 	"testing"
 
 	"github.com/gin-gonic/gin"
@@ -27,13 +29,17 @@ func TestSearchMediaSeriesKeepsRemoteLibrariesSeparate(t *testing.T) {
 			"TotalRecordCount": 1,
 			"Items": []map[string]any{{
 				"Id": "same-series", "Name": "龙珠改", "Type": "Series",
-				"ProviderIds": map[string]string{"Tmdb": "61709"},
+				"ProviderIds":    map[string]string{"Tmdb": "61709"},
+				"ProductionYear": 2024, "Genres": []string{"Science Fiction"},
 			}},
 		})
 	}))
 	defer upstream.Close()
 
-	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
+	// 唯一库名 + cache=shared：远程搜索与本地查询会并发读库，
+	// 而 :memory: 下每个连接各自一个空库，并发连接会读到「no such table」。
+	dsn := fmt.Sprintf("file:%s?mode=memory&cache=shared", strings.ReplaceAll(t.Name(), "/", "_"))
+	db, err := gorm.Open(sqlite.Open(dsn), &gorm.Config{})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -108,4 +114,9 @@ func TestSearchMediaSeriesKeepsRemoteLibrariesSeparate(t *testing.T) {
 		}
 		seen[item.DisplayLibraryID] = true
 	}
+	remoteLibraryID := service.EncodeEmbyRemoteID("mount-a", "view-a")
+	items, total := request("page=1&page_size=8&library_id=" + url.QueryEscape(remoteLibraryID) + "&year_min=2020&genre=Science+Fiction")
+	if total != 1 || len(items) != 1 || items[0].DisplayLibraryID != remoteLibraryID {
+		t.Fatalf("remote library/year/genre filters lost results: total=%d items=%#v", total, items)
+	}
 }

internal/handler/media_test.go

@@ -559,7 +559,10 @@ func TestSearchMediaHandlerIncludesEmbyRemote(t *testing.T) {
 	}))
 	defer server.Close()
 
-	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
+	// 唯一库名 + cache=shared：远程搜索与本地查询会并发读库，
+	// 而 :memory: 下每个连接各自一个空库，并发连接会读到「no such table」。
+	dsn := fmt.Sprintf("file:%s?mode=memory&cache=shared", strings.ReplaceAll(t.Name(), "/", "_"))
+	db, err := gorm.Open(sqlite.Open(dsn), &gorm.Config{})
 	if err != nil {
 		t.Fatal(err)
 	}

internal/handler/playback_extra.go

@@ -80,6 +80,11 @@ func playbackInfoHandler(svc *service.Container) gin.HandlerFunc {
 		// stream_url 跳转，行为与改动前一致。
 		directURL, hasDirectURL := "", false
 		if svc.Stream != nil {
+			// `?refresh=1`：客户端手上的直链已失效（CDN 403），要求丢掉缓存
+			// 重新换链，别把同一条死链再发一次。
+			if strings.EqualFold(strings.TrimSpace(c.Query("refresh")), "1") {
+				service.InvalidateMediaLinkCache(m)
+			}
 			directURL, hasDirectURL = svc.Stream.ResolveDirectPlayURL(c.Request, m)
 		}
 		payload := gin.H{

internal/handler/reader_routes.go

@@ -149,10 +149,10 @@ func readerDeleteSourceHandler(svc *service.Container) gin.HandlerFunc {
 }
 
 func readerDebugSourceHandler(svc *service.Container) gin.HandlerFunc {
-	var body struct {
-		Key string `json:"key" binding:"required"`
-	}
 	return func(c *gin.Context) {
+		var body struct {
+			Key string `json:"key" binding:"required"`
+		}
 		if err := c.ShouldBindJSON(&body); err != nil {
 			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
 			return

internal/handler/routes_admin.go

@@ -13,6 +13,8 @@ func registerAdminRoutes(api *gin.RouterGroup, cfg *config.Config, svc *service.
 	admin := api.Group("/admin")
 	admin.Use(middleware.AuthRequired(cfg.Secrets.JWTSecret), middleware.AdminRequired())
 	registerAdminUserRoutes(admin, svc)
+	admin.GET("/tasks", backgroundTasksHandler(svc))
+	admin.GET("/quality", mediaQualityHandler(svc))
 	registerAdminPermissionRoutes(admin, svc)
 	registerAdminSystemRoutes(admin, svc)
 	registerAdminBackupRoutes(admin, svc)
@@ -143,6 +145,7 @@ func registerAdminSystemRoutes(admin *gin.RouterGroup, svc *service.Container) {
 func registerAdminBackupRoutes(admin *gin.RouterGroup, svc *service.Container) {
 	admin.GET("/backups", listBackupsHandler(svc))
 	admin.POST("/backups", createBackupHandler(svc))
+	admin.GET("/backups/download", downloadBackupHandler(svc))
 	admin.DELETE("/backups", deleteBackupHandler(svc))
 	admin.POST("/backups/restore", restoreBackupHandler(svc))
 }

internal/handler/routes_authenticated_features.go

@@ -21,6 +21,8 @@ func registerAuthedDLNARoutes(authed *gin.RouterGroup, svc *service.Container) {
 }
 
 func registerAuthedRealtimeRoutes(authed *gin.RouterGroup, svc *service.Container) {
-	authed.GET("/ws", wsHandler(svc))
-	authed.GET("/events", sseHandler(svc))
+	// These streams carry operator tasks, including filesystem paths and scan
+	// errors. Their payloads are not scoped to an individual user's libraries.
+	authed.GET("/ws", middleware.AdminRequired(), wsHandler(svc))
+	authed.GET("/events", middleware.AdminRequired(), sseHandler(svc))
 }

internal/handler/streaming.go

@@ -27,7 +27,15 @@ func hlsPlaylistHandler(svc *service.Container) gin.HandlerFunc {
 		if !enforceScopedPlaybackToken(c, m.ID) {
 			return
 		}
-		err = svc.Stream.ServeHLSPlaylist(c.Writer, c.Request, c.Param("id"))
+		scope, ok := localHLSPlaybackScope(c)
+		if !ok {
+			return
+		}
+		err = svc.Stream.ServeHLSPlaylist(c.Writer, c.Request, c.Param("id"), scope)
+		if errors.Is(err, service.ErrHLSGenerationSuperseded) {
+			c.JSON(http.StatusConflict, gin.H{"code": "hls_generation_superseded", "error": err.Error()})
+			return
+		}
 		if errors.Is(err, service.ErrMediaNotFound) {
 			c.JSON(http.StatusNotFound, gin.H{"error": "not found"})
 			return
@@ -62,7 +70,11 @@ func hlsSegmentHandler(svc *service.Container) gin.HandlerFunc {
 		if !enforceScopedPlaybackToken(c, m.ID) {
 			return
 		}
-		err = svc.Stream.ServeHLSSegment(c.Writer, c.Request, c.Param("id"), c.Param("seg"))
+		scope, ok := localHLSPlaybackScope(c)
+		if !ok {
+			return
+		}
+		err = svc.Stream.ServeHLSSegment(c.Writer, c.Request, c.Param("id"), c.Param("seg"), scope)
 		if err != nil {
 			c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
 			return
@@ -72,11 +84,39 @@ func hlsSegmentHandler(svc *service.Container) gin.HandlerFunc {
 
 func stopTranscodeHandler(svc *service.Container) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		svc.Transcoder.StopJob(c.Param("id"))
+		m, err := findMediaForPlaybackEndpoint(c, svc, c.Param("id"))
+		if err != nil || m == nil || !mediaVisibleForRequest(c, svc, m) {
+			c.JSON(http.StatusNotFound, gin.H{"error": "media not found"})
+			return
+		}
+		if !enforceScopedPlaybackToken(c, m.ID) {
+			return
+		}
+		scope, ok := localHLSPlaybackScope(c)
+		if !ok {
+			return
+		}
+		if svc.Transcoder != nil {
+			svc.Transcoder.StopPlayback(m.ID, scope)
+		}
 		c.Status(http.StatusNoContent)
 	}
 }
 
+func localHLSPlaybackScope(c *gin.Context) (service.HLSPlaybackScope, bool) {
+	userID := currentUserID(c)
+	if userID == "" {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "missing playback owner"})
+		return service.HLSPlaybackScope{}, false
+	}
+	scope, err := service.HLSPlaybackScopeForRequest(c.Request, userID)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return service.HLSPlaybackScope{}, false
+	}
+	return scope, true
+}
+
 func imageProxyHandler(svc *service.Container) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		raw := c.Query("url")

internal/handler/ws.go

@@ -1,9 +1,7 @@
 // Package handler — WebSocket endpoint.
 //
-// Clients connect to /api/ws?token=... (the token is the same JWT used for
-// REST calls). The first message they send is a JSON {"action":"subscribe",
-// "topics":["scan","scrape","transcode"]}. Subsequent server-pushed events
-// arrive as {"topic":"...","payload":{...}}.
+// Administrators connect to /api/ws?token=... with their REST access token.
+// Operator events arrive as {"topic":"...","payload":{...}}.
 package handler
 
 import (
@@ -52,8 +50,11 @@ func wsHandler(svc *service.Container) gin.HandlerFunc {
 		sub := svc.WSHub.Subscribe(id, nil)
 		defer svc.WSHub.Unsubscribe(id)
 
-		// Reader: accept ping + subscription updates.
+		// Reading processes WebSocket control frames and detects disconnects.
+		done := make(chan struct{})
+		conn.SetReadLimit(64 << 10)
 		go func() {
+			defer close(done)
 			for {
 				if _, _, err := conn.NextReader(); err != nil {
 					_ = conn.Close()
@@ -67,6 +68,8 @@ func wsHandler(svc *service.Container) gin.HandlerFunc {
 		defer ticker.Stop()
 		for {
 			select {
+			case <-done:
+				return
 			case ev, ok := <-sub.Out:
 				if !ok {
 					return

internal/handler/ws_test.go

@@ -0,0 +1,93 @@
+package handler
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"github.com/golang-jwt/jwt/v5"
+	"github.com/gorilla/websocket"
+	"go.uber.org/zap"
+
+	"github.com/truewhile/MeBox/internal/middleware"
+	"github.com/truewhile/MeBox/internal/service"
+)
+
+func realtimeTestRouter(hub *service.Hub) *gin.Engine {
+	gin.SetMode(gin.TestMode)
+	router := gin.New()
+	authed := router.Group("/api")
+	authed.Use(middleware.AuthRequired("realtime-test"))
+	registerAuthedRealtimeRoutes(authed, &service.Container{WSHub: hub})
+	return router
+}
+
+func realtimeTestToken(t *testing.T, role string) string {
+	t.Helper()
+	token, err := jwt.NewWithClaims(jwt.SigningMethodHS256, middleware.Claims{
+		UserID: "viewer", Role: role,
+		RegisteredClaims: jwt.RegisteredClaims{ExpiresAt: jwt.NewNumericDate(time.Now().Add(time.Hour))},
+	}).SignedString([]byte("realtime-test"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	return token
+}
+
+func TestRealtimeStreamsRejectOrdinaryUsers(t *testing.T) {
+	router := realtimeTestRouter(nil)
+	for _, path := range []string{"/api/ws", "/api/events"} {
+		for _, role := range []string{"", "user"} {
+			req := httptest.NewRequest(http.MethodGet, path, nil)
+			want := http.StatusUnauthorized
+			if role != "" {
+				req.Header.Set("Authorization", "Bearer "+realtimeTestToken(t, role))
+				want = http.StatusForbidden
+			}
+			recorder := httptest.NewRecorder()
+			router.ServeHTTP(recorder, req)
+			if recorder.Code != want {
+				t.Fatalf("%s role %q: status %d, want %d", path, role, recorder.Code, want)
+			}
+		}
+	}
+}
+
+func TestAdminWebSocketReceivesTaskEvents(t *testing.T) {
+	hub := service.NewHub(zap.NewNop())
+	go hub.Run()
+	defer hub.Stop()
+	server := httptest.NewServer(realtimeTestRouter(hub))
+	defer server.Close()
+	url := "ws" + strings.TrimPrefix(server.URL, "http") + "/api/ws?token=" + realtimeTestToken(t, "admin")
+	conn, _, err := websocket.DefaultDialer.Dial(url, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer conn.Close()
+	stop := make(chan struct{})
+	defer close(stop)
+	go func() {
+		ticker := time.NewTicker(10 * time.Millisecond)
+		defer ticker.Stop()
+		for {
+			select {
+			case <-stop:
+				return
+			case <-ticker.C:
+				hub.Publish("task", service.BackgroundTask{ID: "task-1", SourcePath: "/media/private"})
+			}
+		}
+	}()
+	_ = conn.SetReadDeadline(time.Now().Add(2 * time.Second))
+	var event service.Event
+	if err := conn.ReadJSON(&event); err != nil {
+		t.Fatal(err)
+	}
+	if event.Topic != "task" || event.Payload.(map[string]any)["source_path"] != "/media/private" {
+		t.Fatalf("event = %#v", event)
+	}
+}

internal/model/background_task.go

@@ -0,0 +1,23 @@
+package model
+
+import "time"
+
+// BackgroundTaskRecord persists the operator-facing lifecycle of scan,
+// organize, and other long-running application tasks.
+type BackgroundTaskRecord struct {
+	ID         string     `gorm:"primaryKey;size:36" json:"id"`
+	Kind       string     `gorm:"index;size:32;not null" json:"kind"`
+	Name       string     `gorm:"size:255;not null" json:"name"`
+	Status     string     `gorm:"index;size:24;not null" json:"status"`
+	Stage      string     `gorm:"size:64" json:"stage"`
+	SourcePath string     `gorm:"size:2048" json:"source_path"`
+	DestPath   string     `gorm:"size:2048" json:"dest_path"`
+	Message    string     `gorm:"type:text" json:"message"`
+	Error      string     `gorm:"type:text" json:"error"`
+	Details    string     `gorm:"type:text" json:"details"`
+	Metrics    string     `gorm:"type:text" json:"metrics"`
+	Items      string     `gorm:"type:text" json:"items"`
+	StartedAt  time.Time  `gorm:"index" json:"started_at"`
+	UpdatedAt  time.Time  `json:"updated_at"`
+	FinishedAt *time.Time `json:"finished_at,omitempty"`
+}

internal/model/library_media.go

@@ -1,5 +1,7 @@
 package model
 
+import "time"
+
 // Library 表示一个逻辑媒体库。Path 保留为兼容字段，指向第一条 LibraryRoot。
 type Library struct {
 	Base
@@ -26,12 +28,15 @@ type LibraryRoot struct {
 // Media 是单个可播放项。剧集链接到 SeriesID；电影 SeriesID == ""。
 type Media struct {
 	Base
-	LibraryID     string `gorm:"index;size:36;index:idx_media_library_release,priority:1" json:"library_id"`
-	LibraryRootID string `gorm:"index;size:36" json:"library_root_id,omitempty"`
-	SeriesID      string `gorm:"index;size:128" json:"series_id,omitempty"`
-	Title         string `gorm:"size:255;not null" json:"title"`
-	OriginalName  string `gorm:"size:255" json:"original_name,omitempty"`
-	EpisodeTitle  string `gorm:"size:255" json:"episode_title,omitempty"`
+	AvailabilityState string     `gorm:"index;size:16;not null;default:available" json:"availability_state"`
+	MissingSince      *time.Time `json:"missing_since,omitempty"`
+	LastSeenAt        *time.Time `json:"last_seen_at,omitempty"`
+	LibraryID         string     `gorm:"index;size:36;index:idx_media_library_release,priority:1" json:"library_id"`
+	LibraryRootID     string     `gorm:"index;size:36" json:"library_root_id,omitempty"`
+	SeriesID          string     `gorm:"index;size:128" json:"series_id,omitempty"`
+	Title             string     `gorm:"size:255;not null" json:"title"`
+	OriginalName      string     `gorm:"size:255" json:"original_name,omitempty"`
+	EpisodeTitle      string     `gorm:"size:255" json:"episode_title,omitempty"`
 	// Path 的唯一性由 database 包按方言显式建索引，这里刻意不用 uniqueIndex：
 	// PostgreSQL 的 btree 单条索引项上限 2704 字节，而 varchar(1024) 在中文路径
 	// 下可达 3072 字节，直接对整列建唯一索引会让长路径的扫描插入直接失败

internal/model/model.go

@@ -61,6 +61,7 @@ func AllModels() []interface{} {
 		&StrmUploadTask{},
 		&StrmDirCache{},
 		&ScrapeTask{},
+		&BackgroundTaskRecord{},
 		&EmbyMount{},
 		&ReaderBookSource{},
 		&ReaderSourceState{},

internal/repository/media_repository.go

@@ -178,14 +178,6 @@ func (r *MediaRepository) YearRange(ctx context.Context, filter MediaQueryFilter
 	return min, max, nil
 }
 
-func (r *MediaRepository) indexMediaBestEffort(ctx context.Context, media model.Media) {
-	backend, ok := r.searchBackend.(MediaSearchSyncBackend)
-	if !ok {
-		return
-	}
-	_ = backend.IndexMedia(ctx, []model.Media{media})
-}
-
 // FindByID returns the media row or (nil, nil).
 func (r *MediaRepository) FindByID(ctx context.Context, id string) (*model.Media, error) {
 	var m model.Media

internal/repository/media_repository_upsert.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"path/filepath"
 	"strings"
+	"time"
 
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
@@ -96,15 +97,34 @@ func (r *MediaRepository) UpsertBatchWithAliases(ctx context.Context, items []Me
 
 // indexByIDBestEffort 在事务提交后按 ID 回读最新行并同步搜索索引。
 func (r *MediaRepository) indexByIDBestEffort(ctx context.Context, ids []string) {
-	if _, ok := r.searchBackend.(MediaSearchSyncBackend); !ok {
+	backend, ok := r.searchBackend.(MediaSearchSyncBackend)
+	if !ok {
 		return
 	}
+	unique := make([]string, 0, len(ids))
+	seen := make(map[string]struct{}, len(ids))
 	for _, id := range ids {
 		if id == "" {
 			continue
 		}
-		if fresh, err := r.FindByID(ctx, id); err == nil && fresh != nil {
-			r.indexMediaBestEffort(ctx, *fresh)
+		if _, exists := seen[id]; !exists {
+			seen[id] = struct{}{}
+			unique = append(unique, id)
+		}
+	}
+	// Read committed rows and submit one bulk per bounded batch. Keep network
+	// work outside the transaction and below SQLite's parameter limit.
+	const batchSize = 500
+	for start := 0; start < len(unique); start += batchSize {
+		batch := unique[start:min(start+batchSize, len(unique))]
+		rows, err := r.ListMediaByIDs(ctx, batch)
+		if err == nil {
+			err = backend.IndexMedia(ctx, rows)
+		}
+		if err != nil {
+			// The primary write has committed; do not report a failed upsert and
+			// make scanners repeat it. Surface the separate index failure instead.
+			r.db.Logger.Error(ctx, "media saved but search index sync failed for %d items: %v", len(batch), err)
 		}
 	}
 }
@@ -144,6 +164,12 @@ func (r *MediaRepository) upsertWithDB(ctx context.Context, db *gorm.DB, m *mode
 		existing.Path = m.Path
 		existing.DeletedAt = gorm.DeletedAt{}
 	}
+	if _, ok := updates["availability_state"]; ok {
+		existing.AvailabilityState = "available"
+		existing.MissingSince = nil
+		now := updates["last_seen_at"].(time.Time)
+		existing.LastSeenAt = &now
+	}
 	*m = existing
 	return existing.ID, nil
 }
@@ -197,6 +223,10 @@ func (r *MediaRepository) findOrCreateMediaByPath(ctx context.Context, db *gorm.
 		if m.ScrapeStatus == "" {
 			m.ScrapeStatus = "pending"
 		}
+		now := time.Now()
+		m.AvailabilityState = "available"
+		m.MissingSince = nil
+		m.LastSeenAt = &now
 		// PostgreSQL 唯一键异常会中止整个事务，之后重查也会失败。
 		// DO NOTHING 保持事务可用，并兼容 path 的表达式唯一索引。
 		result := db.WithContext(ctx).Clauses(clause.OnConflict{DoNothing: true}).Create(m)
@@ -246,6 +276,11 @@ func (r *MediaRepository) findMediaByAlias(ctx context.Context, db *gorm.DB, cur
 
 func mediaUpsertUpdates(existing, incoming model.Media, reclaimLibrary bool) map[string]any {
 	updates := map[string]any{}
+	if existing.AvailabilityState != "available" || existing.MissingSince != nil {
+		updates["availability_state"] = "available"
+		updates["missing_since"] = nil
+		updates["last_seen_at"] = time.Now()
+	}
 	addMediaFileScanUpdates(updates, existing, incoming)
 	addMediaTitleUpdates(updates, existing, incoming)
 	addMediaExternalIDUpdates(updates, existing, incoming)

internal/repository/opensearch.go

@@ -4,8 +4,10 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
+	"net"
 	"net/http"
 	"net/url"
 	"strings"
@@ -135,14 +137,113 @@ func (b *OpenSearchMediaBackend) EnsureIndex(ctx context.Context) error {
 }
 
 func (b *OpenSearchMediaBackend) IndexMedia(ctx context.Context, rows []model.Media) error {
+	const batchSize = 500
+	var failures []error
+	for start := 0; start < len(rows); start += batchSize {
+		if err := b.indexMediaBatch(ctx, rows[start:min(start+batchSize, len(rows))]); err != nil {
+			failures = append(failures, err)
+			if ctx.Err() != nil {
+				break
+			}
+		}
+	}
+	return errors.Join(failures...)
+}
+
+type openSearchBulkResponse struct {
+	Errors bool `json:"errors"`
+	Items  []struct {
+		Index struct {
+			ID     string `json:"_id"`
+			Status int    `json:"status"`
+			Error  *struct {
+				Type string `json:"type"`
+			} `json:"error"`
+		} `json:"index"`
+	} `json:"items"`
+}
+
+func (b *OpenSearchMediaBackend) indexMediaBatch(ctx context.Context, rows []model.Media) error {
 	if len(rows) == 0 {
 		return nil
 	}
+	pending := rows
+	var failures []error
+	const attempts = 3
+	for attempt := 0; attempt < attempts; attempt++ {
+		if err := ctx.Err(); err != nil {
+			return errors.Join(append(failures, err)...)
+		}
+		if attempt > 0 {
+			timer := time.NewTimer(time.Duration(100*(1<<(attempt-1))) * time.Millisecond)
+			select {
+			case <-ctx.Done():
+				timer.Stop()
+				return errors.Join(append(failures, ctx.Err())...)
+			case <-timer.C:
+			}
+		}
+		response, err := b.submitMediaBulk(ctx, pending)
+		if err != nil {
+			if retryableOpenSearchError(err) && attempt < attempts-1 {
+				continue
+			}
+			return errors.Join(append(failures, err)...)
+		}
+		if len(response.Items) != len(pending) {
+			return errors.Join(append(failures, fmt.Errorf("opensearch bulk returned %d item results for %d documents", len(response.Items), len(pending)))...)
+		}
+		var retry []model.Media
+		failed := false
+		for i, item := range response.Items {
+			result := item.Index
+			if result.Status >= 200 && result.Status < 300 && result.Error == nil {
+				continue
+			}
+			failed = true
+			if retryableOpenSearchStatus(result.Status) && attempt < attempts-1 {
+				retry = append(retry, pending[i])
+				continue
+			}
+			errorType := "unknown"
+			if result.Error != nil {
+				errorType = result.Error.Type
+			}
+			failures = append(failures, fmt.Errorf("opensearch bulk document %q failed: status %d (%s)", pending[i].ID, result.Status, errorType))
+		}
+		if response.Errors && !failed {
+			failures = append(failures, errors.New("opensearch bulk reported errors without failed item results"))
+		}
+		if len(retry) == 0 {
+			break
+		}
+		pending = retry
+	}
+	return errors.Join(failures...)
+}
+
+func retryableOpenSearchStatus(status int) bool {
+	return status == http.StatusRequestTimeout || status == http.StatusTooManyRequests || status >= 500
+}
+
+func retryableOpenSearchError(err error) bool {
+	var statusError *openSearchHTTPError
+	if errors.As(err, &statusError) {
+		return retryableOpenSearchStatus(statusError.status)
+	}
+	var networkError net.Error
+	return errors.As(err, &networkError)
+}
+
+func (b *OpenSearchMediaBackend) submitMediaBulk(ctx context.Context, rows []model.Media) (*openSearchBulkResponse, error) {
+	if len(rows) == 0 {
+		return &openSearchBulkResponse{}, nil
+	}
 	var bulk bytes.Buffer
 	enc := json.NewEncoder(&bulk)
 	for _, row := range rows {
 		if err := enc.Encode(map[string]any{"index": map[string]any{"_index": b.index, "_id": row.ID}}); err != nil {
-			return err
+			return nil, err
 		}
 		if err := enc.Encode(map[string]any{
 			"id":            row.ID,
@@ -155,10 +256,24 @@ func (b *OpenSearchMediaBackend) IndexMedia(ctx context.Context, rows []model.Me
 			"deleted":       row.DeletedAt.Valid,
 			"created_at":    row.CreatedAt,
 		}); err != nil {
-			return err
+			return nil, err
 		}
 	}
-	return b.do(ctx, http.MethodPost, "/_bulk", &bulk, "application/x-ndjson", nil)
+	var response openSearchBulkResponse
+	if err := b.do(ctx, http.MethodPost, "/_bulk", &bulk, "application/x-ndjson", &response); err != nil {
+		return nil, err
+	}
+	return &response, nil
+}
+
+type openSearchHTTPError struct {
+	method string
+	path   string
+	status int
+}
+
+func (e *openSearchHTTPError) Error() string {
+	return fmt.Sprintf("opensearch %s %s returned %d", e.method, e.path, e.status)
 }
 
 func (b *OpenSearchMediaBackend) doJSON(ctx context.Context, method, path string, body any, out any) error {
@@ -190,7 +305,7 @@ func (b *OpenSearchMediaBackend) do(ctx context.Context, method, path string, bo
 	}
 	defer resp.Body.Close()
 	if resp.StatusCode >= 400 {
-		return fmt.Errorf("opensearch %s %s returned %d", method, path, resp.StatusCode)
+		return &openSearchHTTPError{method: method, path: path, status: resp.StatusCode}
 	}
 	if out == nil {
 		_, _ = io.Copy(io.Discard, resp.Body)

internal/repository/opensearch_test.go

@@ -1,12 +1,23 @@
 package repository
 
 import (
+	"bufio"
+	"context"
 	"encoding/json"
+	"errors"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
+	"time"
+
+	"github.com/glebarez/sqlite"
+	"gorm.io/gorm"
+	"gorm.io/gorm/logger"
 
 	"github.com/truewhile/MeBox/internal/config"
+	"github.com/truewhile/MeBox/internal/model"
 )
 
 func TestOpenSearchMediaBackendSearchesIDs(t *testing.T) {
@@ -55,3 +66,156 @@ func TestOpenSearchMediaBackendSearchesIDs(t *testing.T) {
 		t.Fatalf("ids=%#v total=%d", ids, total)
 	}
 }
+
+func bulkRequestIDs(r *http.Request) []string {
+	var ids []string
+	scanner := bufio.NewScanner(r.Body)
+	for scanner.Scan() {
+		var action struct {
+			Index struct {
+				ID string `json:"_id"`
+			} `json:"index"`
+		}
+		_ = json.Unmarshal(scanner.Bytes(), &action)
+		ids = append(ids, action.Index.ID)
+		if !scanner.Scan() {
+			break
+		}
+	}
+	return ids
+}
+
+func writeBulkResults(w http.ResponseWriter, ids []string, statuses map[string]int) {
+	items := make([]any, 0, len(ids))
+	failed := false
+	for _, id := range ids {
+		status := statuses[id]
+		if status == 0 {
+			status = http.StatusCreated
+		}
+		result := map[string]any{"_id": id, "status": status}
+		if status >= 400 {
+			failed = true
+			result["error"] = map[string]any{"type": "test_failure"}
+		}
+		items = append(items, map[string]any{"index": result})
+	}
+	_ = json.NewEncoder(w).Encode(map[string]any{"errors": failed, "items": items})
+}
+
+func TestOpenSearchBulkRetriesOnlyTransientFailedDocuments(t *testing.T) {
+	var requests [][]string
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		ids := bulkRequestIDs(r)
+		requests = append(requests, ids)
+		statuses := map[string]int{}
+		if len(requests) == 1 {
+			statuses["retry"] = http.StatusTooManyRequests
+			statuses["invalid"] = http.StatusBadRequest
+		}
+		writeBulkResults(w, ids, statuses)
+	}))
+	defer upstream.Close()
+	backend := NewOpenSearchMediaBackend(config.SearchConfig{Backend: "opensearch", OpenSearchURL: upstream.URL})
+	rows := []model.Media{{Base: model.Base{ID: "ok"}}, {Base: model.Base{ID: "retry"}}, {Base: model.Base{ID: "invalid"}}}
+	err := backend.IndexMedia(t.Context(), rows)
+	if err == nil || !strings.Contains(err.Error(), `"invalid"`) {
+		t.Fatalf("error = %v, want permanent document failure", err)
+	}
+	if len(requests) != 2 || strings.Join(requests[1], ",") != "retry" {
+		t.Fatalf("requests = %#v; successful/permanent documents must not be retried", requests)
+	}
+}
+
+func TestOpenSearchBulkBoundsRetriesAndRejectsMalformedResponses(t *testing.T) {
+	for _, scenario := range []string{"transient-item", "transient-http", "invalid-http", "missing-results"} {
+		t.Run(scenario, func(t *testing.T) {
+			calls := 0
+			upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				calls++
+				switch scenario {
+				case "transient-item":
+					writeBulkResults(w, bulkRequestIDs(r), map[string]int{"m1": http.StatusServiceUnavailable})
+				case "transient-http":
+					w.WriteHeader(http.StatusServiceUnavailable)
+				case "invalid-http":
+					w.WriteHeader(http.StatusBadRequest)
+				case "missing-results":
+					fmt.Fprint(w, `{"errors":false,"items":[]}`)
+				}
+			}))
+			defer upstream.Close()
+			backend := NewOpenSearchMediaBackend(config.SearchConfig{Backend: "opensearch", OpenSearchURL: upstream.URL})
+			if err := backend.IndexMedia(t.Context(), []model.Media{{Base: model.Base{ID: "m1"}}}); err == nil {
+				t.Fatal("failed indexing was reported as successful")
+			}
+			want := 1
+			if strings.HasPrefix(scenario, "transient") {
+				want = 3
+			}
+			if calls != want {
+				t.Fatalf("calls = %d, want %d", calls, want)
+			}
+		})
+	}
+}
+
+func TestOpenSearchBulkHonorsCancellationDuringRetry(t *testing.T) {
+	ctx, cancel := context.WithCancel(t.Context())
+	defer cancel()
+	calls := 0
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		calls++
+		writeBulkResults(w, bulkRequestIDs(r), map[string]int{"m1": http.StatusTooManyRequests})
+		cancel()
+	}))
+	defer upstream.Close()
+	backend := NewOpenSearchMediaBackend(config.SearchConfig{Backend: "opensearch", OpenSearchURL: upstream.URL})
+	err := backend.IndexMedia(ctx, []model.Media{{Base: model.Base{ID: "m1"}}})
+	if !errors.Is(err, context.Canceled) || calls != 1 {
+		t.Fatalf("error = %v, calls = %d", err, calls)
+	}
+}
+
+func TestMediaUpsertBatchIndexesCommittedRowsTogether(t *testing.T) {
+	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{Logger: logger.Default.LogMode(logger.Silent)})
+	if err != nil {
+		t.Fatal(err)
+	}
+	sqlDB, _ := db.DB()
+	sqlDB.SetMaxOpenConns(1)
+	defer sqlDB.Close()
+	if err := db.AutoMigrate(&model.Media{}); err != nil {
+		t.Fatal(err)
+	}
+	repos := New(db)
+	ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
+	defer cancel()
+	calls := 0
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		calls++
+		ids := bulkRequestIDs(r)
+		if len(ids) != 5 {
+			t.Errorf("bulk contains %d documents, want 5", len(ids))
+		}
+		// With only one DB connection this also detects network work inside the
+		// transaction: a separate read could not observe the committed batch.
+		var count int64
+		if err := db.WithContext(ctx).Model(&model.Media{}).Count(&count).Error; err != nil || count != 5 {
+			t.Errorf("committed rows = %d, error = %v", count, err)
+		}
+		writeBulkResults(w, ids, nil)
+	}))
+	defer upstream.Close()
+	repos.Media.SetSearchBackend(NewOpenSearchMediaBackend(config.SearchConfig{Backend: "opensearch", OpenSearchURL: upstream.URL}))
+	var rows []*model.Media
+	for i := 0; i < 5; i++ {
+		rows = append(rows, &model.Media{LibraryID: "lib", Path: fmt.Sprintf("/media/%d.mkv", i)})
+	}
+	if err := repos.Media.UpsertBatch(ctx, rows); err != nil {
+		t.Fatal(err)
+	}
+	if calls != 1 {
+		t.Fatalf("index requests = %d, want one bulk", calls)
+	}
+}

internal/repository/refresh_token_repository.go

@@ -46,16 +46,20 @@ func (r *RefreshTokenRepository) RevokeByUserID(ctx context.Context, userID stri
 	})
 }
 
-// RevokeOldestActiveByUserID keeps at most limit active refresh tokens for a
-// user by revoking the oldest non-expired, non-revoked tokens.
-func (r *RefreshTokenRepository) RevokeOldestActiveByUserID(ctx context.Context, userID string, limit int) error {
+// RevokeOldestActiveLegacyByUserID keeps at most limit active refresh tokens
+// for a user among tokens that are not bound to a device auth session
+// (legacy web clients). Device sessions are independent: trimming one
+// device's token because another device logged in would silently sign the
+// first device out even though its session is still valid.
+func (r *RefreshTokenRepository) RevokeOldestActiveLegacyByUserID(ctx context.Context, userID string, limit int) error {
 	if limit < 1 {
 		limit = 1
 	}
 	return withSQLiteBusyRetry(ctx, func() error {
 		var tokens []model.RefreshToken
 		if err := r.db.WithContext(ctx).
-			Where("user_id = ? AND revoked = ? AND expires_at > ?", userID, false, time.Now()).
+			Where("user_id = ? AND revoked = ? AND expires_at > ? AND (auth_session_id IS NULL OR auth_session_id = '')",
+				userID, false, time.Now()).
 			Order("created_at desc, id desc").
 			Find(&tokens).Error; err != nil {
 			return err

internal/service/api_config_connection.go

@@ -24,6 +24,14 @@ func (s *ApiConfigService) TestConnection(ctx context.Context, provider string)
 	switch provider {
 	case "tmdb":
 		return s.testTMDb(cfg)
+	case "bangumi":
+		return s.testBangumi(ctx, cfg)
+	case "thetvdb":
+		return s.testTheTVDB(ctx, cfg)
+	case "fanart":
+		return s.testFanart(ctx, cfg)
+	case "douban":
+		return s.testDouban(ctx, cfg)
 	case "openai":
 		return s.testOpenAI(cfg)
 	case "deepseek":

internal/service/api_config_metadata_connection.go

@@ -0,0 +1,191 @@
+package service
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+
+	"github.com/truewhile/MeBox/internal/model"
+)
+
+// Bangumi's public metadata endpoints work without a token. If one was saved,
+// also check /v0/me: public endpoints alone may accept an expired token.
+func (s *ApiConfigService) testBangumi(ctx context.Context, cfg *model.APIConfig) (string, error) {
+	req, err := newMetadataProbeRequest(ctx, cfg, "https://api.bgm.tv", "/v0/subjects/253", http.MethodGet, nil)
+	if err != nil {
+		return "error", err
+	}
+	if token := strings.TrimSpace(cfg.APIKey); token != "" {
+		req.Header.Set("Authorization", "Bearer "+token)
+		identityReq := req.Clone(ctx)
+		identityURL := *req.URL
+		identityURL.Path = strings.TrimSuffix(identityURL.Path, "/subjects/253") + "/me"
+		identityReq.URL = &identityURL
+		var identity struct {
+			ID int `json:"id"`
+		}
+		if result, err := testMetadataProbeJSON(identityReq, "Bangumi", &identity); err != nil {
+			return result, err
+		}
+		if identity.ID <= 0 {
+			return "error", errors.New("Bangumi returned an invalid user response")
+		}
+	}
+	var subject struct {
+		ID   int    `json:"id"`
+		Name string `json:"name"`
+	}
+	if result, err := testMetadataProbeJSON(req, "Bangumi", &subject); err != nil {
+		return result, err
+	}
+	if subject.ID != 253 || strings.TrimSpace(subject.Name) == "" {
+		return "error", errors.New("Bangumi returned an invalid subject response")
+	}
+	return "success", nil
+}
+
+func (s *ApiConfigService) testTheTVDB(ctx context.Context, cfg *model.APIConfig) (string, error) {
+	key := strings.TrimSpace(cfg.APIKey)
+	if key == "" {
+		return "error", errors.New("TheTVDB API key is required")
+	}
+	body, err := json.Marshal(map[string]string{"apikey": key})
+	if err != nil {
+		return "error", err
+	}
+	req, err := newMetadataProbeRequest(ctx, cfg, "https://api4.thetvdb.com/v4", "/login", http.MethodPost, strings.NewReader(string(body)))
+	if err != nil {
+		return "error", err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	var response struct {
+		Status string `json:"status"`
+		Data   struct {
+			Token string `json:"token"`
+		} `json:"data"`
+	}
+	if result, err := testMetadataProbeJSON(req, "TheTVDB", &response); err != nil {
+		return result, err
+	}
+	if response.Status != "success" || strings.TrimSpace(response.Data.Token) == "" {
+		return "error", errors.New("TheTVDB login did not return a valid token")
+	}
+	return "success", nil
+}
+
+func (s *ApiConfigService) testFanart(ctx context.Context, cfg *model.APIConfig) (string, error) {
+	key := strings.TrimSpace(cfg.APIKey)
+	if key == "" {
+		return "error", errors.New("Fanart API key is required")
+	}
+	req, err := newMetadataProbeRequest(ctx, cfg, "https://webservice.fanart.tv/v3", "/movies/550", http.MethodGet, nil)
+	if err != nil {
+		return "error", err
+	}
+	query := req.URL.Query()
+	query.Set("api_key", key)
+	req.URL.RawQuery = query.Encode()
+	var response struct {
+		TMDbID json.Number `json:"tmdb_id"`
+		Name   string      `json:"name"`
+	}
+	if result, err := testMetadataProbeJSON(req, "Fanart", &response); err != nil {
+		return result, err
+	}
+	if response.TMDbID.String() != "550" || strings.TrimSpace(response.Name) == "" {
+		return "error", errors.New("Fanart returned an invalid movie response")
+	}
+	return "success", nil
+}
+
+func (s *ApiConfigService) testDouban(ctx context.Context, cfg *model.APIConfig) (string, error) {
+	req, err := newMetadataProbeRequest(ctx, cfg, "https://movie.douban.com", "/j/subject_suggest", http.MethodGet, nil)
+	if err != nil {
+		return "error", err
+	}
+	query := req.URL.Query()
+	query.Set("q", "Inception")
+	req.URL.RawQuery = query.Encode()
+	req.Header.Set("User-Agent", userAgents[0])
+	req.Header.Set("Referer", "https://movie.douban.com/")
+	req.Header.Set("Accept-Language", "zh-CN,zh;q=0.9,en;q=0.8")
+	if cookie := strings.TrimSpace(cfg.APIKey); cookie != "" {
+		req.Header.Set("Cookie", cookie)
+	}
+	var suggestions []struct {
+		ID    string `json:"id"`
+		Title string `json:"title"`
+	}
+	if result, err := testMetadataProbeJSON(req, "Douban", &suggestions); err != nil {
+		return result, err
+	}
+	// An empty array is a valid search result; null or an error object is not.
+	if suggestions == nil {
+		return "error", errors.New("Douban returned an invalid search response (login or verification may be required)")
+	}
+	for _, suggestion := range suggestions {
+		if suggestion.ID == "" || strings.TrimSpace(suggestion.Title) == "" {
+			return "error", errors.New("Douban returned an invalid search suggestion")
+		}
+	}
+	return "success", nil
+}
+
+func newMetadataProbeRequest(ctx context.Context, cfg *model.APIConfig, defaultBase, path, method string, body io.Reader) (*http.Request, error) {
+	base := strings.TrimRight(strings.TrimSpace(cfg.BaseURL), "/")
+	if base == "" {
+		base = defaultBase
+	}
+	req, err := http.NewRequestWithContext(ctx, method, base+path, body)
+	if err != nil {
+		// The saved base URL may contain credentials. Never echo it to the UI.
+		return nil, fmt.Errorf("%s: invalid base URL", cfg.Provider)
+	}
+	req.Header.Set("User-Agent", "MeBox/0.1 (https://github.com/truewhile/MeBox)")
+	req.Header.Set("Accept", "application/json")
+	return req, nil
+}
+
+// Decode a bounded, complete JSON document rather than accepting any HTTP 200
+// (reverse proxies and anti-bot/login pages often return 200 as well).
+func testMetadataProbeJSON(req *http.Request, provider string, out any) (string, error) {
+	client := NewExternalHTTPClient(10 * time.Second)
+	defer client.CloseIdleConnections()
+	resp, err := client.Do(req)
+	if err != nil {
+		// url.Error includes the full request URL, including Fanart's API key.
+		var urlErr *url.Error
+		if errors.As(err, &urlErr) {
+			err = urlErr.Err
+		}
+		return "error", fmt.Errorf("%s connection failed: %w", provider, err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode == http.StatusUnauthorized {
+		return "invalid", fmt.Errorf("%s authentication failed (HTTP 401): check configured credentials", provider)
+	}
+	if resp.StatusCode == http.StatusForbidden {
+		return "error", fmt.Errorf("%s access denied (HTTP 403): check credentials, permissions or anti-bot verification", provider)
+	}
+	if resp.StatusCode != http.StatusOK {
+		return "error", fmt.Errorf("%s API returned status %d", provider, resp.StatusCode)
+	}
+	body, err := io.ReadAll(io.LimitReader(resp.Body, (1<<20)+1))
+	if err != nil {
+		return "error", fmt.Errorf("%s response read failed: %w", provider, err)
+	}
+	if len(body) > 1<<20 {
+		return "error", fmt.Errorf("%s response exceeds 1 MiB", provider)
+	}
+	if err := json.Unmarshal(body, out); err != nil {
+		// Do not include the response body: it may echo credentials.
+		return "error", fmt.Errorf("%s returned invalid JSON (login or verification page may have intercepted the request)", provider)
+	}
+	return "success", nil
+}

internal/service/api_config_metadata_connection_test.go

@@ -0,0 +1,252 @@
+package service
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"go.uber.org/zap"
+
+	"github.com/truewhile/MeBox/internal/config"
+	"github.com/truewhile/MeBox/internal/repository"
+)
+
+type metadataProbeFixture struct {
+	provider string
+	path     string
+	key      string
+	body     string
+}
+
+var metadataProbeFixtures = []metadataProbeFixture{
+	{"bangumi", "/v0/subjects/253", "", `{"id":253,"name":"カウボーイビバップ","type":2}`},
+	{"thetvdb", "/login", "tvdb-test-secret", `{"status":"success","data":{"token":"test-jwt"}}`},
+	{"fanart", "/movies/550", "fanart+test&secret", `{"name":"Fight Club","tmdb_id":"550","imdb_id":"tt0137523","movieposter":[]}`},
+	{"douban", "/j/subject_suggest", "bid=test-cookie", `[{"id":"3541415","title":"盗梦空间","year":"2010","type":"movie"}]`},
+}
+
+func newMetadataConnectionTestService(t *testing.T) *ApiConfigService {
+	t.Helper()
+	log := zap.NewNop()
+	return NewApiConfigService(&config.Config{}, log, repository.New(newServiceTestDB(t)), NewCryptoService("metadata-test-secret", log))
+}
+
+func saveMetadataProbeConfig(t *testing.T, svc *ApiConfigService, provider, baseURL, key string) {
+	t.Helper()
+	if _, err := svc.Upsert(t.Context(), provider, key, baseURL, "", true); err != nil {
+		t.Fatal(err)
+	}
+}
+
+// Removing a dispatch branch, ignoring the saved URL/key, or using the wrong
+// endpoint must fail this integration test (real database and HTTP server).
+func TestMetadataConnectionUsesSavedConfig(t *testing.T) {
+	svc := newMetadataConnectionTestService(t)
+	for _, fixture := range metadataProbeFixtures {
+		t.Run(fixture.provider, func(t *testing.T) {
+			calls := 0
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				calls++
+				if r.URL.Path != "/proxy"+fixture.path {
+					t.Errorf("request path = %q", r.URL.Path)
+				}
+				if r.Header.Get("User-Agent") == "" {
+					t.Error("missing User-Agent")
+				}
+				if fixture.provider == "thetvdb" {
+					var body map[string]string
+					if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+						t.Error(err)
+					}
+					if r.Method != http.MethodPost || body["apikey"] != fixture.key || r.Header.Get("Content-Type") != "application/json" {
+						t.Error("TheTVDB login must POST the saved, decrypted API key as JSON")
+					}
+				} else if r.Method != http.MethodGet {
+					t.Errorf("method = %s, want GET", r.Method)
+				}
+				if fixture.provider == "fanart" && r.URL.Query().Get("api_key") != fixture.key {
+					t.Error("Fanart API key was not escaped/passed correctly")
+				}
+				if fixture.provider == "douban" {
+					if r.Header.Get("Cookie") != fixture.key || r.Header.Get("Referer") != "https://movie.douban.com/" || r.URL.Query().Get("q") == "" {
+						t.Error("Douban search must carry the configured cookie, referer and query")
+					}
+				}
+				w.Header().Set("Content-Type", "application/json")
+				_, _ = w.Write([]byte(fixture.body))
+			}))
+			defer server.Close()
+			saveMetadataProbeConfig(t, svc, fixture.provider, "  "+server.URL+"/proxy/  ", fixture.key)
+			result, err := svc.TestConnection(t.Context(), fixture.provider)
+			if err != nil || result != "success" {
+				t.Fatalf("TestConnection = %q, %v, want success", result, err)
+			}
+			if calls != 1 {
+				t.Errorf("HTTP calls = %d, want 1", calls)
+			}
+		})
+	}
+}
+
+func TestMetadataConnectionRejectsBadResponses(t *testing.T) {
+	svc := newMetadataConnectionTestService(t)
+	for _, fixture := range metadataProbeFixtures {
+		for _, response := range []struct {
+			name   string
+			status int
+			body   string
+			result string
+		}{
+			{"unauthorized", 401, `{"error":"denied"}`, "invalid"},
+			{"forbidden", 403, `<html>Access denied</html>`, "error"},
+			{"rate limited", 429, `{}`, "error"},
+			{"upstream error", 503, `{}`, "error"},
+			{"challenge page", 200, `<html>Please log in or complete verification</html>`, "error"},
+			{"empty body", 200, ``, "error"},
+			{"wrong schema", 200, `{"error":"intercepted"}`, "error"},
+			{"null", 200, `null`, "error"},
+			{"trailing garbage", 200, fixture.body + `<html>blocked</html>`, "error"},
+		} {
+			t.Run(fixture.provider+"/"+response.name, func(t *testing.T) {
+				server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+					w.WriteHeader(response.status)
+					_, _ = w.Write([]byte(response.body))
+				}))
+				defer server.Close()
+				saveMetadataProbeConfig(t, svc, fixture.provider, server.URL, fixture.key)
+				result, err := svc.TestConnection(t.Context(), fixture.provider)
+				if err == nil || result != response.result {
+					t.Fatalf("TestConnection = %q, %v, want %q and error", result, err, response.result)
+				}
+				if fixture.key != "" && strings.Contains(err.Error(), fixture.key) {
+					t.Error("error exposes configured credentials")
+				}
+			})
+		}
+	}
+}
+
+func TestMetadataConnectionRequiresAPIKeys(t *testing.T) {
+	svc := newMetadataConnectionTestService(t)
+	for _, provider := range []string{"thetvdb", "fanart"} {
+		t.Run(provider, func(t *testing.T) {
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				t.Error("must reject missing key before making a request")
+			}))
+			defer server.Close()
+			saveMetadataProbeConfig(t, svc, provider, server.URL, "  ")
+			result, err := svc.TestConnection(t.Context(), provider)
+			if result != "error" || err == nil || !strings.Contains(err.Error(), "API key") {
+				t.Fatalf("TestConnection = %q, %v, want missing API key error", result, err)
+			}
+		})
+	}
+}
+
+func TestMetadataConnectionBangumiValidatesConfiguredToken(t *testing.T) {
+	svc := newMetadataConnectionTestService(t)
+	for _, valid := range []bool{true, false} {
+		name := "valid"
+		if !valid {
+			name = "invalid"
+		}
+		t.Run(name, func(t *testing.T) {
+			meCalls, subjectCalls := 0, 0
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				if r.Header.Get("Authorization") != "Bearer bangumi-test-token" {
+					t.Error("missing saved Bangumi bearer token")
+				}
+				switch r.URL.Path {
+				case "/v0/me":
+					meCalls++
+					if !valid {
+						w.WriteHeader(http.StatusUnauthorized)
+						return
+					}
+					_, _ = w.Write([]byte(`{"id":42,"username":"test-user"}`))
+				case "/v0/subjects/253":
+					subjectCalls++
+					_, _ = w.Write([]byte(`{"id":253,"name":"カウボーイビバップ"}`))
+				default:
+					t.Errorf("unexpected path: %s", r.URL.Path)
+					w.WriteHeader(http.StatusNotFound)
+				}
+			}))
+			defer server.Close()
+			saveMetadataProbeConfig(t, svc, "bangumi", server.URL, "bangumi-test-token")
+			result, err := svc.TestConnection(t.Context(), "bangumi")
+			if valid && (result != "success" || err != nil || subjectCalls != 1) {
+				t.Fatalf("valid token: result=%q err=%v subjectCalls=%d", result, err, subjectCalls)
+			}
+			if !valid && (result != "invalid" || err == nil || subjectCalls != 0) {
+				t.Fatalf("invalid token: result=%q err=%v subjectCalls=%d", result, err, subjectCalls)
+			}
+			if meCalls != 1 {
+				t.Errorf("identity requests = %d, want 1", meCalls)
+			}
+		})
+	}
+}
+
+func TestMetadataConnectionDoubanDoesNotRequireCookie(t *testing.T) {
+	svc := newMetadataConnectionTestService(t)
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Header.Get("Cookie") != "" {
+			t.Error("unexpected Cookie for public search")
+		}
+		_, _ = w.Write([]byte(`[]`))
+	}))
+	defer server.Close()
+	saveMetadataProbeConfig(t, svc, "douban", server.URL, "")
+	result, err := svc.TestConnection(t.Context(), "douban")
+	if result != "success" || err != nil {
+		t.Fatalf("public search with empty results = %q, %v", result, err)
+	}
+}
+
+func TestMetadataConnectionHonorsContext(t *testing.T) {
+	svc := newMetadataConnectionTestService(t)
+	for _, fixture := range metadataProbeFixtures {
+		t.Run(fixture.provider, func(t *testing.T) {
+			started := make(chan struct{})
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				_, _ = io.Copy(io.Discard, r.Body)
+				close(started)
+				<-r.Context().Done()
+			}))
+			defer server.Close()
+			saveMetadataProbeConfig(t, svc, fixture.provider, server.URL, fixture.key)
+			ctx, cancel := context.WithTimeout(t.Context(), 2*time.Second)
+			defer cancel()
+			go func() {
+				select {
+				case <-started:
+					cancel()
+				case <-ctx.Done():
+				}
+			}()
+			result, err := svc.TestConnection(ctx, fixture.provider)
+			if result != "error" || !errors.Is(err, context.Canceled) {
+				t.Fatalf("cancelled request = %q, %v, want context.Canceled", result, err)
+			}
+		})
+	}
+}
+
+func TestMetadataConnectionTransportErrorsHideKeys(t *testing.T) {
+	svc := newMetadataConnectionTestService(t)
+	server := httptest.NewServer(http.NotFoundHandler())
+	server.Close()
+	key := "sensitive-fanart-key"
+	saveMetadataProbeConfig(t, svc, "fanart", server.URL, key)
+	result, err := svc.TestConnection(t.Context(), "fanart")
+	if result != "error" || err == nil || strings.Contains(err.Error(), key) {
+		t.Fatalf("transport failure = %q, %v, want error without credentials", result, err)
+	}
+}

internal/service/auth_session_test.go

@@ -3,6 +3,7 @@ package service
 import (
 	"context"
 	"errors"
+	"fmt"
 	"testing"
 	"time"
 
@@ -163,6 +164,52 @@ func TestRefreshKeepsSessionAssociation(t *testing.T) {
 	}
 }
 
+// TestMobileDeviceSessionsDoNotTrimEachOther 覆盖同一账号多设备登录：
+// 每台设备有独立认证会话与刷新令牌，新设备登录或任一设备刷新都不应撤销
+// 其他设备的刷新令牌。历史实现把「最大同时登录终端」直接作用在刷新令牌
+// 上，第 N+1 台设备登录会把最早那台设备的刷新令牌标记为已撤销，那台设备
+// 下一次刷新就会收到 SESSION_REVOKED，被强制退回登录页。
+func TestMobileDeviceSessionsDoNotTrimEachOther(t *testing.T) {
+	sessions, tokens, repos := newAuthSessionTestEnv(t)
+	ctx := context.Background()
+	user := seedSessionUser(t, repos)
+
+	// 默认上限是 3，这里故意登录 4 台设备。
+	const devices = 4
+	pairs := make([]*TokenPair, 0, devices)
+	for i := 0; i < devices; i++ {
+		session, err := sessions.Create(ctx, CreateAuthSessionInput{
+			UserID:     user.ID,
+			DeviceID:   fmt.Sprintf("device-%02d", i),
+			DeviceName: fmt.Sprintf("Phone %d", i+1),
+		})
+		if err != nil {
+			t.Fatalf("create session %d: %v", i+1, err)
+		}
+		pair, err := tokens.IssuePairForSession(ctx, user.ID, user.Role, user.Tier, session.ID)
+		if err != nil {
+			t.Fatalf("issue pair %d: %v", i+1, err)
+		}
+		pairs = append(pairs, pair)
+	}
+
+	for i, pair := range pairs {
+		row, err := repos.RefreshToken.FindByHash(ctx, repository.HashToken(pair.RefreshToken))
+		if err != nil {
+			t.Fatalf("load device %d token: %v", i+1, err)
+		}
+		if row == nil {
+			t.Fatalf("device %d refresh token missing", i+1)
+		}
+		if row.Revoked {
+			t.Fatalf("device %d refresh token was revoked by another device", i+1)
+		}
+		if _, err := tokens.Refresh(ctx, pair.RefreshToken); err != nil {
+			t.Fatalf("device %d refresh failed: %v", i+1, err)
+		}
+	}
+}
+
 func TestServerIdentityPersistsAcrossInstances(t *testing.T) {
 	db := newServiceTestDB(t, &model.Setting{})
 	repos := repository.New(db)

internal/service/backup.go

@@ -5,7 +5,7 @@
 //
 // 两种方言的备份形态不同：
 //   - SQLite：用 "VACUUM INTO"（3.27.0 起可用）产出一个一致的库文件，
-//     扩展名 .db；恢复即「替换库文件 + 重启」。
+//     扩展名 .db；恢复先暂存，在下次启动打开数据库前替换文件。
 //   - PostgreSQL：没有单文件语义，用逻辑备份（见 backup_postgres.go），
 //     扩展名 .json.gz；恢复是在单个事务内重建全部表。
 package service
@@ -24,6 +24,7 @@ import (
 	"gorm.io/gorm"
 
 	"github.com/truewhile/MeBox/internal/config"
+	"github.com/truewhile/MeBox/internal/database"
 )
 
 // BackupService manages database backups.
@@ -44,6 +45,7 @@ type BackupInfo struct {
 	Path      string    `json:"path"`
 	Size      int64     `json:"size"`
 	CreatedAt time.Time `json:"created_at"`
+	Automatic bool      `json:"automatic"`
 }
 
 func (b *BackupService) backupDir() string {
@@ -69,6 +71,23 @@ func (b *BackupService) backupFilePath(filename string) (string, error) {
 	return path, nil
 }
 
+// ResolvePath returns the absolute path of a listed backup after applying the
+// same filename and directory checks used by restore and delete operations.
+func (b *BackupService) ResolvePath(filename string) (string, error) {
+	path, err := b.backupFilePath(filename)
+	if err != nil {
+		return "", err
+	}
+	info, err := os.Lstat(path)
+	if err != nil {
+		return "", err
+	}
+	if !info.Mode().IsRegular() {
+		return "", errors.New("backup is not a regular file")
+	}
+	return path, nil
+}
+
 // isPostgres reports whether the service is backed by PostgreSQL.
 //
 // PostgreSQL 不支持 SQLite 的 "VACUUM INTO"，按文件替换恢复也会写错目标，
@@ -80,11 +99,23 @@ func (b *BackupService) isPostgres() bool {
 // Create produces a new hot backup. SQLite uses "VACUUM INTO"; PostgreSQL uses
 // a logical dump.
 func (b *BackupService) Create(ctx context.Context) (*BackupInfo, error) {
+	return b.create(ctx, false)
+}
+
+func (b *BackupService) CreateAutomatic(ctx context.Context) (*BackupInfo, error) {
+	return b.create(ctx, true)
+}
+
+func (b *BackupService) create(ctx context.Context, automatic bool) (*BackupInfo, error) {
 	dir := b.backupDir()
 	if err := os.MkdirAll(dir, 0o750); err != nil {
 		return nil, err
 	}
-	ts := time.Now().Format("20060102_150405")
+	now := time.Now()
+	ts := fmt.Sprintf("%s_%09d", now.Format("20060102_150405"), now.Nanosecond())
+	if automatic {
+		ts = "auto_" + ts
+	}
 
 	var (
 		dst string
@@ -108,15 +139,24 @@ func (b *BackupService) Create(ctx context.Context) (*BackupInfo, error) {
 		Path:      dst,
 		Size:      stat.Size(),
 		CreatedAt: stat.ModTime(),
+		Automatic: automatic,
 	}, nil
 }
 
 func (b *BackupService) createSQLiteBackup(ctx context.Context, stamp string) (string, error) {
 	dst := filepath.Join(b.backupDir(), fmt.Sprintf("mebox_%s.db", stamp))
-	// VACUUM INTO creates a clean, non-WAL copy atomically.
-	if err := b.db.WithContext(ctx).Exec("VACUUM INTO ?", dst).Error; err != nil {
+	tmp := dst + ".tmp"
+	defer os.Remove(tmp)
+	// Publish only completed backups, with credentials protected by file mode.
+	if err := b.db.WithContext(ctx).Exec("VACUUM INTO ?", tmp).Error; err != nil {
 		return "", fmt.Errorf("VACUUM INTO failed: %w", err)
 	}
+	if err := os.Chmod(tmp, 0o600); err != nil {
+		return "", err
+	}
+	if err := os.Rename(tmp, dst); err != nil {
+		return "", err
+	}
 	return dst, nil
 }
 
@@ -132,7 +172,7 @@ func (b *BackupService) List() ([]BackupInfo, error) {
 	}
 	out := make([]BackupInfo, 0, len(entries))
 	for _, e := range entries {
-		if e.IsDir() || !isBackupFilename(e.Name()) {
+		if !e.Type().IsRegular() || !isBackupFilename(e.Name()) {
 			continue
 		}
 		info, err := e.Info()
@@ -144,6 +184,7 @@ func (b *BackupService) List() ([]BackupInfo, error) {
 			Path:      filepath.Join(dir, e.Name()),
 			Size:      info.Size(),
 			CreatedAt: info.ModTime(),
+			Automatic: strings.HasPrefix(e.Name(), "mebox_auto_"),
 		})
 	}
 	sort.Slice(out, func(i, j int) bool {
@@ -152,6 +193,36 @@ func (b *BackupService) List() ([]BackupInfo, error) {
 	return out, nil
 }
 
+// Prune keeps maxCount automatic backups for the current database dialect.
+// Manual backups and backups from another dialect are never pruned.
+// A value below one disables pruning so an invalid setting cannot erase all
+// recoverable copies.
+func (b *BackupService) Prune(maxCount int) error {
+	if maxCount < 1 {
+		return nil
+	}
+	items, err := b.List()
+	if err != nil {
+		return err
+	}
+	eligible := items[:0]
+	for _, item := range items {
+		if item.Automatic && strings.HasSuffix(item.Filename, postgresBackupSuffix) == b.isPostgres() {
+			eligible = append(eligible, item)
+		}
+	}
+	items = eligible
+	if maxCount >= len(items) {
+		return nil
+	}
+	for _, item := range items[maxCount:] {
+		if err := b.Delete(item.Filename); err != nil && !errors.Is(err, os.ErrNotExist) {
+			return err
+		}
+	}
+	return nil
+}
+
 // Delete removes a single backup file.
 func (b *BackupService) Delete(filename string) error {
 	path, err := b.backupFilePath(filename)
@@ -161,12 +232,10 @@ func (b *BackupService) Delete(filename string) error {
 	return os.Remove(path)
 }
 
-// Restore replaces the live database with the given backup.
-// WARNING: this is destructive. SQLite restores by swapping the database file
-// (the caller should shut down the server afterwards); PostgreSQL restores by
-// rebuilding every table inside a single transaction.
+// Restore stages SQLite backups for the next startup. PostgreSQL restores
+// rebuild every table inside a single transaction.
 func (b *BackupService) Restore(ctx context.Context, filename string) error {
-	src, err := b.backupFilePath(filename)
+	src, err := b.ResolvePath(filename)
 	if err != nil {
 		return err
 	}
@@ -182,35 +251,10 @@ func (b *BackupService) Restore(ctx context.Context, filename string) error {
 	if !strings.HasSuffix(filename, ".db") {
 		return errors.New("该备份是 PostgreSQL 逻辑备份，当前运行在 SQLite 上，无法恢复")
 	}
-	return b.restoreSQLiteBackup(filename, src)
-}
-
-func (b *BackupService) restoreSQLiteBackup(filename, src string) error {
-	dbPath, err := filepath.Abs(b.cfg.Database.DBPath)
-	if err != nil || dbPath == "" {
-		return errors.New("invalid database path")
-	}
-	// Strategy: rename live → live.old, copy backup → live, delete old.
-	old := dbPath + ".before_restore"
-	if err := os.Rename(dbPath, old); err != nil && !errors.Is(err, os.ErrNotExist) {
+	if err := database.StageSQLiteRestore(ctx, b.cfg, src); err != nil {
 		return err
 	}
-	data, err := os.ReadFile(src) // #nosec G304 -- src is constrained by backupFilePath to the configured backups directory.
-	if err != nil {
-		// Revert
-		_ = os.Rename(old, dbPath)
-		return err
-	}
-	if err := os.WriteFile(dbPath, data, 0o600); err != nil { // #nosec G703 -- database path is trusted process config and normalized before restore.
-		_ = os.Rename(old, dbPath)
-		return err
-	}
-	_ = os.Remove(old)
-	// Also remove WAL/SHM so SQLite opens the fresh file cleanly.
-	_ = os.Remove(dbPath + "-wal")
-	_ = os.Remove(dbPath + "-shm")
-	b.log.Warn("database restored from backup — restart the server",
-		zap.String("backup", filename))
+	b.log.Warn("SQLite backup staged; restart to apply", zap.String("backup", filename))
 	return nil
 }
 

internal/service/backup_postgres.go

@@ -3,6 +3,7 @@ package service
 import (
 	"compress/gzip"
 	"context"
+	"database/sql"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -87,7 +88,8 @@ func postgresBackupModelSchemas(db *gorm.DB) (map[string]*schema.Schema, map[str
 // createPostgresBackup 把全库导出成一个 gzip 压缩的 JSON Lines 文件。
 func (b *BackupService) createPostgresBackup(ctx context.Context, stamp string) (string, error) {
 	dst := filepath.Join(b.backupDir(), "mebox_"+stamp+postgresBackupSuffix)
-	file, err := os.OpenFile(dst, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0o600)
+	tmp := dst + ".tmp"
+	file, err := os.OpenFile(tmp, os.O_CREATE|os.O_EXCL|os.O_WRONLY, 0o600)
 	if err != nil {
 		return "", err
 	}
@@ -96,7 +98,7 @@ func (b *BackupService) createPostgresBackup(ctx context.Context, stamp string)
 		_ = file.Close()
 		if !complete {
 			// 半截备份文件比没有备份更危险：留着会让人以为有可用的还原点。
-			_ = os.Remove(dst)
+			_ = os.Remove(tmp)
 		}
 	}()
 
@@ -109,17 +111,30 @@ func (b *BackupService) createPostgresBackup(ctx context.Context, stamp string)
 	}); err != nil {
 		return "", fmt.Errorf("写入备份头失败: %w", err)
 	}
-	for _, m := range model.AllModels() {
-		table, sch, err := parseModelSchema(b.db, m)
-		if err != nil {
-			return "", err
-		}
-		if !b.db.Migrator().HasTable(table) {
-			continue
-		}
-		if err := b.dumpPostgresTable(ctx, m, sch, table, enc); err != nil {
-			return "", err
+	var options []*sql.TxOptions
+	if b.isPostgres() {
+		options = append(options, &sql.TxOptions{Isolation: sql.LevelRepeatableRead, ReadOnly: true})
+	}
+	// Every table must come from the same snapshot, including while background
+	// workers are inserting related rows during an automatic backup.
+	if err := b.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
+		snapshot := *b
+		snapshot.db = tx
+		for _, m := range model.AllModels() {
+			table, sch, err := parseModelSchema(tx, m)
+			if err != nil {
+				return err
+			}
+			if !tx.Migrator().HasTable(table) {
+				continue
+			}
+			if err := snapshot.dumpPostgresTable(ctx, m, sch, table, enc); err != nil {
+				return err
+			}
 		}
+		return nil
+	}, options...); err != nil {
+		return "", err
 	}
 	if err := zw.Close(); err != nil {
 		return "", fmt.Errorf("压缩备份失败: %w", err)
@@ -127,6 +142,12 @@ func (b *BackupService) createPostgresBackup(ctx context.Context, stamp string)
 	if err := file.Sync(); err != nil {
 		return "", fmt.Errorf("写入备份失败: %w", err)
 	}
+	if err := file.Close(); err != nil {
+		return "", err
+	}
+	if err := os.Rename(tmp, dst); err != nil {
+		return "", err
+	}
 	complete = true
 	return dst, nil
 }

internal/service/backup_retention_test.go

@@ -0,0 +1,65 @@
+package service
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+	"testing"
+	"time"
+)
+
+func TestBackupRetentionPreservesManualAndOtherDialectBackups(t *testing.T) {
+	svc, _ := newBackupTestService(t)
+	names := []string{"mebox_auto_new.db", "mebox_auto_old.db", "mebox_manual.db", "mebox_auto_postgres.json.gz"}
+	for i, name := range names {
+		path := filepath.Join(svc.backupDir(), name)
+		if err := os.WriteFile(path, []byte("fixture"), 0o600); err != nil {
+			t.Fatal(err)
+		}
+		when := time.Now().Add(-time.Duration(i) * time.Hour)
+		if err := os.Chtimes(path, when, when); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := svc.Prune(1); err != nil {
+		t.Fatal(err)
+	}
+	for _, name := range names {
+		_, err := os.Stat(filepath.Join(svc.backupDir(), name))
+		if name == "mebox_auto_old.db" {
+			if !os.IsNotExist(err) {
+				t.Fatalf("old automatic backup was retained: %v", err)
+			}
+		} else if err != nil {
+			t.Fatalf("backup %s should have been preserved: %v", name, err)
+		}
+	}
+}
+
+func TestBackupCreateUsesUniquePrivateCompletedFiles(t *testing.T) {
+	svc, _ := newBackupTestService(t)
+	manual, err := svc.Create(t.Context())
+	if err != nil {
+		t.Fatal(err)
+	}
+	automatic, err := svc.CreateAutomatic(t.Context())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if manual.Filename == automatic.Filename || manual.Automatic || !automatic.Automatic {
+		t.Fatalf("invalid backup identities: manual=%#v automatic=%#v", manual, automatic)
+	}
+	items, err := svc.List()
+	if err != nil || len(items) != 2 {
+		t.Fatalf("completed backup list: items=%#v err=%v", items, err)
+	}
+	for _, item := range items {
+		info, err := os.Stat(item.Path)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if runtime.GOOS != "windows" && info.Mode().Perm() != 0o600 {
+			t.Fatalf("backup permissions are not private: %s err=%v", item.Path, err)
+		}
+	}
+}

internal/service/cloud115/url_cache.go

@@ -1,26 +1,34 @@
 // 下载直链进程级缓存。
 //
-// 115 的 /open/ufile/downurl 换取结果在一段时间内有效，且换取请求是
-// WAF 风控重点关注的密集接口。缓存按 pickcode 存直链、避免对同一文件
-// 反复换取；下载失败（http 403/404 等）时由调用方主动清除对应条目，
-// 下一轮重试会重新换取链接。
+// 115 的 /open/ufile/downurl 换取结果带 `t=` 过期时间戳（实测为「换取时刻 +
+// 1800 秒」，即 30 分钟），且换取请求是 WAF 风控重点关注的密集接口。缓存按
+// pickcode 存直链、避免对同一文件反复换取；下载失败（http 403/404 等）时由
+// 调用方主动清除对应条目，下一轮重试会重新换取链接。
 package cloud115
 
 import (
+	"net/url"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
 )
 
-// downloadURLCacheTTL 直链缓存时长。115 直链一般有效 1 小时左右，
-// 取 45 分钟留出余量。QMediaSync 同类缓存使用 50 分钟。
-const downloadURLCacheTTL = 45 * time.Minute
+// downloadURLCacheMaxTTL 直链缓存上限：仅在解析不出直链自带过期时间（`t=`）
+// 时使用。115 直链实际有效 30 分钟，这里取 45 分钟只是兜底上限，正常情况下
+// 由 linkExpirySafety 提前失效，避免把已经过期的直链发给客户端。
+const downloadURLCacheMaxTTL = 45 * time.Minute
+
+// linkExpirySafety 提前量：直链自身的过期时间戳到达前就停止使用，留出客户端
+// 建连与传输的余量，防止出现「服务端认为还有效、CDN 已经 403」的窗口。
+const linkExpirySafety = 2 * time.Minute
 
 // maxCachedURLs 超过该数量时顺带清理过期条目，防止 map 无限膨胀。
 const maxCachedURLs = 10000
 
 type urlCacheEntry struct {
 	url       string
+	createdAt time.Time
 	expiresAt time.Time
 }
 
@@ -37,6 +45,43 @@ func urlCacheKey(pickCode, ua string) string {
 	return pickCode + "@" + ua
 }
 
+// LinkExpiry 解析 115 直链自带的过期时间戳（`t=` 参数，单位秒）。
+// 解析不出时返回零值，调用方按兜底 TTL 处理。
+func LinkExpiry(rawURL string) time.Time {
+	u, err := url.Parse(strings.TrimSpace(rawURL))
+	if err != nil || u == nil {
+		return time.Time{}
+	}
+	raw := strings.TrimSpace(u.Query().Get("t"))
+	if raw == "" {
+		return time.Time{}
+	}
+	sec, err := strconv.ParseInt(raw, 10, 64)
+	if err != nil || sec <= 0 {
+		return time.Time{}
+	}
+	return time.Unix(sec, 0)
+}
+
+// cacheExpiry 计算写入缓存时应使用的过期时刻：跟随直链自身的 `t=` 并提前
+// linkExpirySafety，解析不出时退回 downloadURLCacheMaxTTL。返回零值表示这条
+// 直链已经过期，不应写入缓存。
+func cacheExpiry(rawURL string, now time.Time) time.Time {
+	maxExpiry := now.Add(downloadURLCacheMaxTTL)
+	linkExpiry := LinkExpiry(rawURL)
+	if linkExpiry.IsZero() {
+		return maxExpiry
+	}
+	expiry := linkExpiry.Add(-linkExpirySafety)
+	if !expiry.After(now) {
+		return time.Time{}
+	}
+	if expiry.After(maxExpiry) {
+		return maxExpiry
+	}
+	return expiry
+}
+
 // GetDownloadURLCache 返回未过期的缓存直链；不存在或已过期返回空串。
 func GetDownloadURLCache(pickCode string, uas ...string) string {
 	if pickCode == "" {
@@ -59,11 +104,17 @@ func GetDownloadURLCache(pickCode string, uas ...string) string {
 	return entry.url
 }
 
-// SetDownloadURLCache 写入直链缓存。
+// SetDownloadURLCache 写入直链缓存。过期时刻跟随直链自身的 `t=`，已经过期的
+// 直链直接丢弃，避免把死链缓存下来。
 func SetDownloadURLCache(pickCode string, url string, uas ...string) {
 	if pickCode == "" || url == "" {
 		return
 	}
+	now := time.Now()
+	expiresAt := cacheExpiry(url, now)
+	if expiresAt.IsZero() {
+		return
+	}
 	ua := ""
 	if len(uas) > 0 {
 		ua = uas[0]
@@ -71,7 +122,6 @@ func SetDownloadURLCache(pickCode string, url string, uas ...string) {
 	urlCacheMu.Lock()
 	defer urlCacheMu.Unlock()
 	if len(urlCache) >= maxCachedURLs {
-		now := time.Now()
 		for k, e := range urlCache {
 			if now.After(e.expiresAt) {
 				delete(urlCache, k)
@@ -79,7 +129,7 @@ func SetDownloadURLCache(pickCode string, url string, uas ...string) {
 		}
 	}
 	key := urlCacheKey(pickCode, ua)
-	urlCache[key] = urlCacheEntry{url: url, expiresAt: time.Now().Add(downloadURLCacheTTL)}
+	urlCache[key] = urlCacheEntry{url: url, createdAt: now, expiresAt: expiresAt}
 }
 
 // ClearDownloadURLCache 删除指定 pickcode 的所有缓存（下载得到非 2xx 时调用）。
@@ -95,3 +145,32 @@ func ClearDownloadURLCache(pickCode string) {
 		}
 	}
 }
+
+// ClearDownloadURLCacheIfOlderThan 删除指定 pickcode 下「已经存在超过 minAge」
+// 的缓存条目，返回是否删除了至少一条。
+//
+// 客户端上报「直链被 CDN 拒绝」时用它强制换链：既让下一次解析拿到新地址，
+// 又不会让同一秒内的重试风暴把 115 换链接口打出突发。
+func ClearDownloadURLCacheIfOlderThan(pickCode string, minAge time.Duration) bool {
+	if pickCode == "" {
+		return false
+	}
+	if minAge < 0 {
+		minAge = 0
+	}
+	now := time.Now()
+	removed := false
+	urlCacheMu.Lock()
+	defer urlCacheMu.Unlock()
+	for k, e := range urlCache {
+		if k != pickCode && !strings.HasPrefix(k, pickCode+"@") {
+			continue
+		}
+		if now.Sub(e.createdAt) < minAge {
+			continue
+		}
+		delete(urlCache, k)
+		removed = true
+	}
+	return removed
+}

internal/service/cloud115/url_cache_test.go

@@ -1,6 +1,7 @@
 package cloud115
 
 import (
+	"fmt"
 	"testing"
 	"time"
 )
@@ -29,3 +30,72 @@ func TestDownloadURLCache(t *testing.T) {
 		t.Fatalf("cleared entry should be a miss, got %q", got)
 	}
 }
+
+// 115 直链自带 `t=` 过期时间戳（实测为换取时刻 + 1800 秒）。缓存必须跟随它，
+// 否则会出现「服务端认为还有效、CDN 已经 403」的窗口：直链被缓存到 45 分钟，
+// 但第 30 分钟起客户端就必然拿到 403。
+func TestDownloadURLCacheExpiryFollowsLinkTimestamp(t *testing.T) {
+	now := time.Now()
+	link := fmt.Sprintf("https://cdn/1/a.mkv?t=%d&u=1&k=abc", now.Add(30*time.Minute).Unix())
+
+	got := cacheExpiry(link, now)
+	want := now.Add(30*time.Minute - linkExpirySafety)
+	if diff := got.Sub(want); diff > time.Second || diff < -time.Second {
+		t.Fatalf("cacheExpiry = %v, want %v", got, want)
+	}
+
+	// 解析不出 t= 时退回兜底 TTL，保持旧行为。
+	fallback := cacheExpiry("https://cdn/1/a.mkv", now)
+	if diff := fallback.Sub(now.Add(downloadURLCacheMaxTTL)); diff > time.Second || diff < -time.Second {
+		t.Fatalf("fallback cacheExpiry = %v, want %v", fallback, now.Add(downloadURLCacheMaxTTL))
+	}
+
+	// 直链本身已经过期（或只剩不足提前量的寿命）时不进缓存。
+	if got := cacheExpiry(fmt.Sprintf("https://cdn/1/a.mkv?t=%d", now.Add(-time.Minute).Unix()), now); !got.IsZero() {
+		t.Fatalf("expired link must not be cached, got expiry %v", got)
+	}
+	if got := cacheExpiry(fmt.Sprintf("https://cdn/1/a.mkv?t=%d", now.Add(time.Minute).Unix()), now); !got.IsZero() {
+		t.Fatalf("link expiring inside the safety margin must not be cached, got %v", got)
+	}
+}
+
+// 客户端上报「直链被 CDN 拒绝」时按 pickcode 清缓存，但要挡住刚写入的条目，
+// 避免重试风暴把 115 换链接口打出突发。
+func TestClearDownloadURLCacheIfOlderThan(t *testing.T) {
+	urlCacheMu.Lock()
+	urlCache = map[string]urlCacheEntry{}
+	urlCacheMu.Unlock()
+	t.Cleanup(func() {
+		urlCacheMu.Lock()
+		urlCache = map[string]urlCacheEntry{}
+		urlCacheMu.Unlock()
+	})
+
+	future := time.Now().Add(30 * time.Minute)
+	link := fmt.Sprintf("https://cdn/1/a.mkv?t=%d", future.Unix())
+	SetDownloadURLCache("pick-fresh", link, "ua-a")
+	if ClearDownloadURLCacheIfOlderThan("pick-fresh", time.Minute) {
+		t.Fatal("fresh entry must survive the min-age guard")
+	}
+	if got := GetDownloadURLCache("pick-fresh", "ua-a"); got != link {
+		t.Fatalf("fresh entry lost, got %q", got)
+	}
+
+	SetDownloadURLCache("pick-old", link, "ua-a")
+	urlCacheMu.Lock()
+	entry := urlCache[urlCacheKey("pick-old", "ua-a")]
+	entry.createdAt = time.Now().Add(-10 * time.Minute)
+	urlCache[urlCacheKey("pick-old", "ua-a")] = entry
+	urlCacheMu.Unlock()
+
+	if !ClearDownloadURLCacheIfOlderThan("pick-old", time.Minute) {
+		t.Fatal("stale entry should be cleared")
+	}
+	if got := GetDownloadURLCache("pick-old", "ua-a"); got != "" {
+		t.Fatalf("stale entry should be gone, got %q", got)
+	}
+	// 无关 pickcode 不受影响。
+	if got := GetDownloadURLCache("pick-fresh", "ua-a"); got != link {
+		t.Fatalf("unrelated pickcode lost, got %q", got)
+	}
+}

internal/service/cloud115_hls_authorization_test.go

@@ -0,0 +1,33 @@
+package service
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestCloud115HLSChildRejectsMismatchedSessionMediaBeforeFetch(t *testing.T) {
+	fetched := false
+	proxy := &Cloud115HLSProxy{sessions: map[string]*cloud115HLSSession{}}
+	proxy.client = &http.Client{Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
+		fetched = true
+		return &http.Response{StatusCode: http.StatusOK, Header: http.Header{"Content-Type": []string{"video/mp2t"}}, Body: io.NopCloser(strings.NewReader("private-segment")), Request: req}, nil
+	})}
+	proxy.sessions["session-b"] = &cloud115HLSSession{
+		ID: "session-b", MediaID: "media-b", ExpiresAt: time.Now().Add(time.Hour),
+		entries: map[string]string{"segment": "https://cpats01.115.com/seg.ts"},
+	}
+	for _, query := range []string{"?media_id=media-a", ""} {
+		fetched = false
+		req := httptest.NewRequest(http.MethodGet, "/api/cloud115/hls/session-b/segment"+query, nil)
+		rec := httptest.NewRecorder()
+		err := proxy.ServeChild(context.Background(), rec, req, "session-b", "segment")
+		if err == nil || fetched {
+			t.Errorf("query %q must reject the wrong/missing media before fetch; err=%v fetched=%v", query, err, fetched)
+		}
+	}
+}

internal/service/cloud115_hls_proxy.go

@@ -20,8 +20,9 @@ import (
 )
 
 var (
-	ErrCloud115HLSSessionNotFound = errors.New("115 hls session not found")
-	ErrCloud115HLSUpstreamExpired = errors.New("115 hls upstream expired")
+	ErrCloud115HLSSessionNotFound      = errors.New("115 hls session not found")
+	ErrCloud115HLSUpstreamExpired      = errors.New("115 hls upstream expired")
+	ErrCloud115HLSSessionMediaMismatch = errors.New("115 hls session media mismatch")
 )
 
 const (
@@ -131,6 +132,9 @@ func (p *Cloud115HLSProxy) ServeChild(ctx context.Context, w http.ResponseWriter
 	if !ok {
 		return ErrCloud115HLSSessionNotFound
 	}
+	if r == nil || strings.TrimSpace(r.URL.Query().Get("media_id")) != session.MediaID {
+		return ErrCloud115HLSSessionMediaMismatch
+	}
 	resp, err := p.fetchUpstream(ctx, upstream, r.Header.Get("Range"))
 	if err != nil {
 		return err
@@ -186,6 +190,15 @@ func (p *Cloud115HLSProxy) ServeChild(ctx context.Context, w http.ResponseWriter
 	return err
 }
 
+// SessionMediaID resolves the server-owned media identity before handler authorization.
+func (p *Cloud115HLSProxy) SessionMediaID(sessionID, key string) (string, error) {
+	session, _, ok := p.lookup(sessionID, key)
+	if !ok {
+		return "", ErrCloud115HLSSessionNotFound
+	}
+	return session.MediaID, nil
+}
+
 func (p *Cloud115HLSProxy) newSession(mediaID string, definition int) *cloud115HLSSession {
 	now := time.Now()
 	return &cloud115HLSSession{

internal/service/cloud115_playback.go

@@ -104,11 +104,13 @@ func (s *Cloud115PlaybackService) HLSProxy() *Cloud115HLSProxy {
 	return s.proxy
 }
 
-// PlaybackInfo 返回媒体在 direct/115-cloud/local 三种模式下的能力描述。
-//
-// requestedDefinition 为空或 0 时默认选择 1080P；该档位不可用时返回
-// transcoding 状态（并只触发一次加速转码，避免轮询风暴）。
+// PlaybackInfo only reads direct/115-cloud/local playback capabilities.
+// Cloud work is queued exclusively by StartTranscode, never by polling.
 func (s *Cloud115PlaybackService) PlaybackInfo(ctx context.Context, mediaID string, requestedDefinition int) (*PlaybackInfo, error) {
+	return s.playbackInfo(ctx, mediaID, requestedDefinition, false)
+}
+
+func (s *Cloud115PlaybackService) playbackInfo(ctx context.Context, mediaID string, requestedDefinition int, startTranscode bool) (*PlaybackInfo, error) {
 	if s == nil || s.repo == nil || s.repo.Media == nil {
 		return nil, ErrMediaNotFound
 	}
@@ -179,13 +181,26 @@ func (s *Cloud115PlaybackService) PlaybackInfo(ctx context.Context, mediaID stri
 		return info, nil
 	}
 
-	info.Transcode = s.ensureCloudTranscode(ctx, account.ID, pickCode, selected, client)
+	if startTranscode {
+		info.Transcode = s.ensureCloudTranscode(ctx, account.ID, pickCode, selected, client)
+	} else {
+		info.Transcode = Cloud115TranscodeState{
+			State: "idle", Definition: selected.ID, Message: "该清晰度尚未就绪，可请求 115 云端转码", RetryAfterSec: 5,
+		}
+		s.mu.Lock()
+		if last, ok := s.pushState[account.ID+":"+pickCode]; ok {
+			info.Transcode.State = "transcoding"
+			info.Transcode.Message = last.message
+			info.Transcode.StartedAt = last.at.Unix()
+		}
+		s.mu.Unlock()
+	}
 	return info, nil
 }
 
 // StartTranscode 显式触发某个清晰度的云端转码，返回最新状态。
 func (s *Cloud115PlaybackService) StartTranscode(ctx context.Context, mediaID string, definition int) (*PlaybackInfo, error) {
-	return s.PlaybackInfo(ctx, mediaID, definition)
+	return s.playbackInfo(ctx, mediaID, definition, true)
 }
 
 // ResolveCloud115URL 返回指定清晰度的 115 云端 m3u8 地址。
@@ -258,6 +273,9 @@ func (s *Cloud115PlaybackService) ensureCloudTranscode(
 			}
 		}
 	}
+	// Reserve the in-flight attempt before releasing the lock. Two simultaneous
+	// explicit starts must not both submit a push while the first awaits 115.
+	s.pushState[key] = cloud115PushAttempt{at: now, message: "正在提交 115 云端转码请求…"}
 	s.mu.Unlock()
 
 	err := client.SubmitVideoPush(ctx, pickCode, "vip_push")

internal/service/cloud115_playback_test.go

@@ -16,7 +16,7 @@ import (
 	"github.com/truewhile/MeBox/internal/service/cloud115"
 )
 
-func TestCloud115PlaybackInfoTriggersTranscodeOnce(t *testing.T) {
+func TestCloud115PlaybackInfoIsReadOnlyAndStartTriggersTranscodeOnce(t *testing.T) {
 	var playCalls int32
 	var pushCalls int32
 	var ready int32
@@ -93,9 +93,16 @@ func TestCloud115PlaybackInfoTriggersTranscodeOnce(t *testing.T) {
 	}
 	svc := NewCloud115PlaybackService(nil, zap.NewNop(), repos, strm)
 
-	info, err := svc.PlaybackInfo(ctx, media.ID, 0)
+	if _, err := svc.PlaybackInfo(ctx, media.ID, 0); err != nil {
+		t.Fatalf("read playback info: %v", err)
+	}
+	if got := atomic.LoadInt32(&pushCalls); got != 0 {
+		t.Fatalf("read-only playback info triggered %d cloud transcode pushes", got)
+	}
+
+	info, err := svc.StartTranscode(ctx, media.ID, 0)
 	if err != nil {
-		t.Fatalf("first playback info: %v", err)
+		t.Fatalf("start transcode: %v", err)
 	}
 	if info.Provider != model.StrmProvider115 || info.DefaultQuality != "4" {
 		t.Fatalf("unexpected playback info: %#v", info)

internal/service/cloud115_transcode_concurrency_test.go

@@ -0,0 +1,77 @@
+package service
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"go.uber.org/zap"
+
+	"github.com/truewhile/MeBox/internal/service/cloud115"
+)
+
+func TestCloud115ConcurrentStartsDoNotDuplicateInFlightPush(t *testing.T) {
+	started := make(chan struct{})
+	release := make(chan struct{})
+	var releaseOnce sync.Once
+	var pushCalls atomic.Int32
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if pushCalls.Add(1) == 1 {
+			close(started)
+		}
+		<-release
+		w.Header().Set("Content-Type", "application/json")
+		_ = json.NewEncoder(w).Encode(map[string]any{"state": true, "code": 0, "data": []any{}})
+	}))
+	defer server.Close()
+	defer releaseOnce.Do(func() { close(release) })
+	oldBase := cloud115.ProAPIBase
+	cloud115.ProAPIBase = server.URL
+	defer func() { cloud115.ProAPIBase = oldBase }()
+	client := cloud115.NewOpenClient("review-app", "access", "refresh")
+	svc := NewCloud115PlaybackService(nil, zap.NewNop(), nil, nil)
+	quality := PlaybackQuality{ID: "4", Label: "1080P", Source: "cloud"}
+	ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
+	defer cancel()
+	first := make(chan struct{})
+	go func() { defer close(first); svc.ensureCloudTranscode(ctx, "account", "pick", quality, client) }()
+	select {
+	case <-started:
+	case <-ctx.Done():
+		t.Fatal("first push did not reach the local server")
+	}
+	second := make(chan Cloud115TranscodeState, 1)
+	go func() { second <- svc.ensureCloudTranscode(ctx, "account", "pick", quality, client) }()
+	secondReceived := false
+	select {
+	case state := <-second:
+		secondReceived = true
+		if state.State != "transcoding" {
+			t.Errorf("in-flight request should be reported as transcoding: %#v", state)
+		}
+	case <-time.After(250 * time.Millisecond):
+		t.Error("second start issued another request instead of reusing the in-flight push")
+	}
+	releaseOnce.Do(func() { close(release) })
+	select {
+	case <-first:
+	case <-ctx.Done():
+		t.Fatal("first push did not finish")
+	}
+	// The duplicate path is awaited before restoring the package-wide fake API.
+	if !secondReceived {
+		select {
+		case <-second:
+		case <-ctx.Done():
+			t.Fatal("second start did not finish")
+		}
+	}
+	if got := pushCalls.Load(); got != 1 {
+		t.Fatalf("pushes=%d, want 1", got)
+	}
+}

internal/service/hls_session.go

@@ -0,0 +1,109 @@
+package service
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+	"unicode"
+)
+
+var ErrInvalidHLSPlaybackScope = errors.New("invalid HLS playback scope")
+var ErrHLSGenerationSuperseded = errors.New("HLS playback generation superseded")
+
+// HLSPlaybackScope separates a media's independent users and player instances.
+// UserID must come from server authentication, never from a request parameter.
+type HLSPlaybackScope struct {
+	UserID    string
+	SessionID string
+}
+
+func HLSPlaybackScopeForRequest(r *http.Request, userID string) (HLSPlaybackScope, error) {
+	scope := HLSPlaybackScope{UserID: strings.TrimSpace(userID)}
+	if scope.UserID == "" || r == nil {
+		return scope, ErrInvalidHLSPlaybackScope
+	}
+	for _, key := range []string{"session_id", "PlaySessionId", "playSessionId", "DeviceId", "deviceId"} {
+		if value := strings.TrimSpace(r.URL.Query().Get(key)); value != "" {
+			scope.SessionID = value
+			break
+		}
+	}
+	if scope.SessionID == "" {
+		if device := strings.TrimSpace(r.Header.Get("X-Emby-Device-Id")); device != "" {
+			scope.SessionID = device
+		}
+	}
+	if len(scope.SessionID) > 256 || strings.IndexFunc(scope.SessionID, unicode.IsControl) >= 0 {
+		return scope, ErrInvalidHLSPlaybackScope
+	}
+	// Clients without a session/device identifier remain compatible but only
+	// share a legacy task with the same authenticated user, never other users.
+	return scope, nil
+}
+
+func (scope HLSPlaybackScope) jobKey(mediaID string) string {
+	if scope.UserID == "" && scope.SessionID == "" {
+		return mediaID // Existing internal callers/tests retain their legacy API.
+	}
+	sum := sha256.Sum256([]byte(scope.UserID + "\x00" + mediaID + "\x00" + scope.SessionID))
+	return "player-" + hex.EncodeToString(sum[:])
+}
+
+func hlsPlaybackJobKey(mediaID string, scopes []HLSPlaybackScope) string {
+	if len(scopes) == 0 {
+		return mediaID
+	}
+	return scopes[0].jobKey(mediaID)
+}
+
+func (job *hlsJob) key() string {
+	if job.jobKey != "" {
+		return job.jobKey
+	}
+	return job.mediaID
+}
+
+func (t *TranscoderService) jobPlaylistPath(job *hlsJob) string {
+	dir := job.outputDir
+	if dir == "" {
+		dir = t.HLSDir(job.key())
+	}
+	return filepath.Join(dir, "index.m3u8")
+}
+
+// hlsOutputDir captures one immutable run directory. Even if a new run starts
+// after this check, the request cannot accidentally open its replacement files.
+func (t *TranscoderService) hlsOutputDir(key string, generation int64) (string, error) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	job := t.jobs[key]
+	if job == nil {
+		return "", ErrMediaNotFound
+	}
+	if job.seekGen != generation {
+		return "", ErrHLSGenerationSuperseded
+	}
+	t.touchJobLocked(key)
+	if job.outputDir != "" {
+		return job.outputDir, nil
+	}
+	return t.HLSDir(key), nil
+}
+
+func (t *TranscoderService) StopPlayback(mediaID string, scope HLSPlaybackScope) {
+	key := scope.jobKey(mediaID)
+	unlock := t.lockJobStart(key)
+	defer unlock()
+	t.mu.Lock()
+	job := t.detachJobLocked(key)
+	t.mu.Unlock()
+	waitJobExit(job, 12*time.Second)
+	// Keep cleanup under the same gate as start: a delayed stop must not wipe
+	// an output directory created by a concurrent replacement request.
+	_ = os.RemoveAll(t.HLSDir(key))
+}

internal/service/hls_session_lifecycle_test.go

@@ -0,0 +1,133 @@
+package service
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	"go.uber.org/zap"
+
+	"github.com/truewhile/MeBox/internal/config"
+	"github.com/truewhile/MeBox/internal/model"
+	"github.com/truewhile/MeBox/internal/repository"
+)
+
+func cachedScopedHLS(t *testing.T, scopes ...HLSPlaybackScope) (*StreamService, *TranscoderService, map[string]string) {
+	t.Helper()
+	cfg := &config.Config{}
+	cfg.Cache.CacheDir = t.TempDir()
+	cfg.Transcoder.Enabled = true
+	db := newServiceTestDB(t)
+	if err := db.Create(&model.Media{Base: model.Base{ID: "movie"}, Path: "unused-cached-source", DurationSec: 60}).Error; err != nil {
+		t.Fatal(err)
+	}
+	transcoder := NewTranscoderService(cfg, zap.NewNop(), repository.New(db), nil)
+	paths := map[string]string{}
+	for _, scope := range scopes {
+		key := scope.jobKey("movie")
+		dir := filepath.Join(transcoder.HLSDir(key), "run-cached")
+		if err := os.MkdirAll(dir, 0o750); err != nil {
+			t.Fatal(err)
+		}
+		playlist := filepath.Join(dir, "index.m3u8")
+		if err := os.WriteFile(playlist, []byte("#EXTM3U\n#EXTINF:4,\nseg_00000.ts\n"), 0o600); err != nil {
+			t.Fatal(err)
+		}
+		if err := os.WriteFile(filepath.Join(dir, "seg_00000.ts"), []byte(scope.UserID+"/"+scope.SessionID), 0o600); err != nil {
+			t.Fatal(err)
+		}
+		transcoder.jobs[key] = &hlsJob{mediaID: "movie", jobKey: key, outputDir: dir, subtitleStream: -1, startedAt: time.Now(), cancel: func() {}}
+		paths[key] = playlist
+	}
+	return NewStreamService(cfg, zap.NewNop(), repository.New(db), transcoder), transcoder, paths
+}
+
+func TestHLSPlaybackEnsureReusesOnlyMatchingOwnerAndSession(t *testing.T) {
+	a := HLSPlaybackScope{UserID: "viewer", SessionID: "tab-a"}
+	b := HLSPlaybackScope{UserID: "viewer", SessionID: "tab-b"}
+	_, transcoder, paths := cachedScopedHLS(t, a, b)
+	for _, scope := range []HLSPlaybackScope{a, b} {
+		playlist, err := transcoder.EnsureJobFromSubtitleQuality(t.Context(), "movie", 0, 0, -1, "", scope)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if playlist != paths[scope.jobKey("movie")] {
+			t.Fatalf("scope %#v reused another session's playlist %q", scope, playlist)
+		}
+	}
+}
+
+func TestHLSPlaybackStopRemovesOnlyItsSessionOutput(t *testing.T) {
+	a := HLSPlaybackScope{UserID: "viewer", SessionID: "tab-a"}
+	b := HLSPlaybackScope{UserID: "viewer", SessionID: "tab-b"}
+	_, transcoder, paths := cachedScopedHLS(t, a, b)
+	transcoder.StopPlayback("movie", a)
+	if _, err := os.Stat(paths[a.jobKey("movie")]); !os.IsNotExist(err) {
+		t.Fatalf("stopped session output must be cleaned up, err=%v", err)
+	}
+	if _, err := os.Stat(paths[b.jobKey("movie")]); err != nil {
+		t.Fatalf("another player's output was removed: %v", err)
+	}
+}
+
+func TestHLSPlaybackIdleCleanupRemovesExpiredSessionOutput(t *testing.T) {
+	a := HLSPlaybackScope{UserID: "viewer", SessionID: "tab-a"}
+	b := HLSPlaybackScope{UserID: "viewer", SessionID: "tab-b"}
+	_, transcoder, paths := cachedScopedHLS(t, a, b)
+	job := transcoder.jobs[a.jobKey("movie")]
+	job.lastAccess = time.Now().Add(-2 * time.Minute)
+	if !transcoder.stopIdleJob(job, time.Minute) {
+		t.Fatal("expired session was not stopped")
+	}
+	if _, err := os.Stat(paths[a.jobKey("movie")]); !os.IsNotExist(err) {
+		t.Fatalf("expired output was retained: %v", err)
+	}
+	if _, err := os.Stat(paths[b.jobKey("movie")]); err != nil {
+		t.Fatalf("active session output was removed: %v", err)
+	}
+}
+
+func TestHLSPlaybackPropagatesHeaderDeviceIdentityToSegments(t *testing.T) {
+	req := httptest.NewRequest(http.MethodGet, "/api/hls/movie/index.m3u8?token=test", nil)
+	req.Header.Set("X-Emby-Device-Id", "legacy-device")
+	scope, err := HLSPlaybackScopeForRequest(req, "viewer")
+	if err != nil {
+		t.Fatal(err)
+	}
+	svc, _, _ := cachedScopedHLS(t, scope)
+	rec := httptest.NewRecorder()
+	if err := svc.ServeHLSPlaylist(rec, req, "movie", scope); err != nil {
+		t.Fatal(err)
+	}
+	var segment string
+	for _, line := range strings.Split(rec.Body.String(), "\n") {
+		if strings.HasPrefix(line, "seg_") {
+			segment = line
+			break
+		}
+	}
+	u, err := url.Parse(segment)
+	if err != nil || u.Query().Get("session_id") == "" {
+		t.Fatalf("playlist must carry the header-only device scope to child URLs: %q err=%v", segment, err)
+	}
+	child := httptest.NewRequest(http.MethodGet, "/api/hls/movie/"+segment, nil)
+	childScope, err := HLSPlaybackScopeForRequest(child, "viewer")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if childScope.jobKey("movie") != scope.jobKey("movie") {
+		t.Fatal("child request changed its owner's device scope")
+	}
+	childRec := httptest.NewRecorder()
+	if err := svc.ServeHLSSegment(childRec, child, "movie", "seg_00000.ts", childScope); err != nil {
+		t.Fatal(err)
+	}
+	if childRec.Body.String() != "viewer/"+scope.SessionID {
+		t.Fatalf("wrong scoped segment: %s", childRec.Body.String())
+	}
+}

internal/service/hls_session_test.go

@@ -0,0 +1,97 @@
+package service
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"go.uber.org/zap"
+
+	"github.com/truewhile/MeBox/internal/config"
+)
+
+func TestHLSPlaybackScopesIsolateSegmentReadsAndStop(t *testing.T) {
+	cfg := &config.Config{}
+	cfg.Cache.CacheDir = t.TempDir()
+	transcoder := NewTranscoderService(cfg, zap.NewNop(), nil, nil)
+	svc := NewStreamService(cfg, zap.NewNop(), nil, transcoder)
+	a := HLSPlaybackScope{UserID: "user-a", SessionID: "tab-a"}
+	b := HLSPlaybackScope{UserID: "user-b", SessionID: "tab-a"}
+	c := HLSPlaybackScope{UserID: "user-a", SessionID: "tab-c"}
+	for _, scope := range []HLSPlaybackScope{a, b, c} {
+		key := scope.jobKey("movie")
+		dir := filepath.Join(cfg.Cache.CacheDir, key, "run-current")
+		if err := os.MkdirAll(dir, 0o750); err != nil {
+			t.Fatal(err)
+		}
+		if err := os.WriteFile(filepath.Join(dir, "seg_00000.ts"), []byte(scope.UserID+"/"+scope.SessionID), 0o600); err != nil {
+			t.Fatal(err)
+		}
+		transcoder.jobs[key] = &hlsJob{mediaID: "movie", jobKey: key, outputDir: dir, seekGen: 100, cancel: func() {}}
+	}
+	for _, scope := range []HLSPlaybackScope{a, b, c} {
+		req := httptest.NewRequest(http.MethodGet, "/api/hls/movie/seg_00000.ts?_seek=100", nil)
+		rec := httptest.NewRecorder()
+		if err := svc.ServeHLSSegment(rec, req, "movie", "seg_00000.ts", scope); err != nil {
+			t.Fatal(err)
+		}
+		if got, want := rec.Body.String(), scope.UserID+"/"+scope.SessionID; got != want {
+			t.Fatalf("segment=%q, want %q", got, want)
+		}
+	}
+	transcoder.StopPlayback("movie", a)
+	if transcoder.jobs[a.jobKey("movie")] != nil {
+		t.Fatal("stopped scope is still active")
+	}
+	if transcoder.jobs[b.jobKey("movie")] == nil || transcoder.jobs[c.jobKey("movie")] == nil {
+		t.Fatal("stopping one player affected another user/tab")
+	}
+	// A delayed stop from a previous local-playback session must not affect a replacement.
+	transcoder.StopPlayback("movie", a)
+	if transcoder.jobs[c.jobKey("movie")] == nil {
+		t.Fatal("old stop cancelled a new session")
+	}
+}
+
+func TestHLSPlaybackRejectsStaleSegmentGeneration(t *testing.T) {
+	cfg := &config.Config{}
+	cfg.Cache.CacheDir = t.TempDir()
+	transcoder := NewTranscoderService(cfg, zap.NewNop(), nil, nil)
+	svc := NewStreamService(cfg, zap.NewNop(), nil, transcoder)
+	scope := HLSPlaybackScope{UserID: "viewer", SessionID: "tab"}
+	key := scope.jobKey("movie")
+	dir := t.TempDir()
+	if err := os.WriteFile(filepath.Join(dir, "seg_00000.ts"), []byte("new-generation"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	transcoder.jobs[key] = &hlsJob{mediaID: "movie", jobKey: key, outputDir: dir, seekGen: 200, cancel: func() {}}
+	req := httptest.NewRequest(http.MethodGet, "/api/hls/movie/seg_00000.ts?_seek=100", nil)
+	rec := httptest.NewRecorder()
+	if err := svc.ServeHLSSegment(rec, req, "movie", "seg_00000.ts", scope); err == nil {
+		t.Fatal("stale segment request read a replacement generation")
+	}
+	if rec.Body.Len() != 0 {
+		t.Fatal("stale request exposed replacement bytes")
+	}
+}
+
+func TestHLSPlaybackScopeRequiresServerOwner(t *testing.T) {
+	req := httptest.NewRequest(http.MethodGet, "/?session_id=tab&user_id=attacker-controlled", nil)
+	if _, err := HLSPlaybackScopeForRequest(req, ""); err == nil {
+		t.Fatal("missing authenticated owner was accepted")
+	}
+	a, err := HLSPlaybackScopeForRequest(req, "real-owner")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if a.UserID != "real-owner" {
+		t.Fatal("client parameter supplied the owner")
+	}
+	req = httptest.NewRequest(http.MethodGet, "/?PlaySessionId=emby-session", nil)
+	b, err := HLSPlaybackScopeForRequest(req, "real-owner")
+	if err != nil || b.SessionID == "" {
+		t.Fatalf("Emby session must stay scoped: %#v %v", b, err)
+	}
+}

internal/service/image_proxy.go

@@ -49,6 +49,10 @@ type ImageProxy struct {
 	resizeSemMu sync.Mutex
 	resizeSem   chan struct{}
 
+	// resizeQueueWait 是一次请求最多为一格解码槽排队的时长。为 0 时用
+	// defaultResizeQueueWait；测试会把它调小以免真的等待两秒。
+	resizeQueueWait time.Duration
+
 	// libraryRootsFn returns the configured media library roots so that
 	// sidecar poster/artwork files stored alongside media (under arbitrary
 	// per-library paths) are allowed by isAllowedLocalPath. It is provided
@@ -86,6 +90,12 @@ const (
 	// imageRenditionCacheSubdir 存放挂载 Emby 直接按尺寸产出的成品图：它们
 	// 已经是客户端要的最终尺寸，和派生缩略图一样属于长期保留的热路径缓存。
 	imageRenditionCacheSubdir = "renditions"
+
+	// defaultResizeQueueWait 是请求为一格解码槽排队的最长时间。一张 3MP
+	// 海报的解码+缩放约 0.15s，2 核机器两格槽位足以在几秒内消化一整屏
+	// 海报；等待远好于「槽位忙就回退多兆字节原图」（那样每张图在外部网络
+	// 下要十几秒）。超时后仍回退原图，保证请求不会被无限期挂住。
+	defaultResizeQueueWait = 3 * time.Second
 )
 
 // NewImageProxy is the constructor.

internal/service/image_resize.go

@@ -17,6 +17,7 @@ import (
 	"path/filepath"
 	"strconv"
 	"strings"
+	"time"
 
 	"go.uber.org/zap"
 
@@ -138,8 +139,8 @@ func fitSize(srcW, srcH, maxW, maxH int) (int, int) {
 
 var errImageResizeTooLarge = errors.New("image source exceeds resize pixel budget")
 
-// resizeImageData 按选项缩放图片并重新编码。返回 unchanged=true 表示原图
-// 本身已满足目标尺寸，调用方应直接输出原始字节（不重复编码、不损失质量）。
+// resizeImageData 按选项缩放图片并重新编码。返回 unchanged=true 表示源图
+// 已经是可直接下发的紧凑字节，调用方应直接输出原始字节（不重复编码）。
 func resizeImageData(data []byte, o imageResizeOptions) (out []byte, ctype string, unchanged bool, err error) {
 	if len(data) == 0 || !o.active() {
 		return data, detectContentType(data), true, nil
@@ -151,12 +152,21 @@ func resizeImageData(data []byte, o imageResizeOptions) (out []byte, ctype strin
 	if cfg.Width <= 0 || cfg.Height <= 0 {
 		return nil, "", false, errors.New("invalid image dimensions")
 	}
-	// 先用 DecodeConfig 判断是否需要解码整图：图已够小就零成本返回原字节。
+	// 先用 DecodeConfig 判断是否需要缩放。尺寸已在目标框内时仍要重编码：
+	// 刮削来源的海报常是 1000×1500、1MB 以上的 PNG，直接原样下发会让一处
+	// 海报墙就从「几十 KB 缩略图」变成「几十 MB 原图」——外部网络下每张
+	// 都要十几秒。只有本来就是紧凑 Web 格式（JPEG/WebP）且体积很小的源图
+	// 才值得零成本直出。
 	dstW, dstH := fitSize(cfg.Width, cfg.Height, o.MaxWidth, o.MaxHeight)
-	if dstW == cfg.Width && dstH == cfg.Height {
+	unchangedSize := dstW == cfg.Width && dstH == cfg.Height
+	if unchangedSize && isCompactWebFormat(format) && len(data) <= compactImageSkipBytes {
 		return data, detectContentType(data), true, nil
 	}
 	if int64(cfg.Width)*int64(cfg.Height) > imageResizeMaxSourcePixels {
+		if unchangedSize {
+			// 尺寸已满足但像素量超出解码预算：宁可直出原图，也不冒 OOM 风险。
+			return data, detectContentType(data), true, nil
+		}
 		return nil, "", false, errImageResizeTooLarge
 	}
 
@@ -165,7 +175,12 @@ func resizeImageData(data []byte, o imageResizeOptions) (out []byte, ctype strin
 		return nil, "", false, err
 	}
 	dst := image.NewRGBA(image.Rect(0, 0, dstW, dstH))
-	resizeScaled(dst, src, cfg.Width, cfg.Height)
+	if unchangedSize {
+		// 不缩放时省掉一次全图重采样，只做格式转换。
+		draw.Draw(dst, dst.Bounds(), src, src.Bounds().Min, draw.Src)
+	} else {
+		resizeScaled(dst, src, cfg.Width, cfg.Height)
+	}
 
 	// 只有可能带透明的源格式才需要逐像素确认，避免 JPEG 的无谓遍历。
 	// 写实海报的 PNG 通常比等价 JPEG 大一个数量级，因此在确认不含透明
@@ -231,9 +246,12 @@ func isOpaqueImage(img *image.RGBA) bool {
 // resizeSourceKey 生成源图身份键：只覆盖源文件身份（路径 + 大小 + mtime），不含
 // 目标尺寸。同一源图的所有尺寸档位共用这个前缀，才能互相列举与派生（小图直接
 // 从已缓存的大图缩小，而不是重新解码原图）。
+//
+// 前缀里的 v3 是缓存格式版本：v2 时期「尺寸已在目标框内」的 PNG 会原样直出、
+// 不写缓存，而现在同样条件会重编码成 JPEG，旧缓存与新结果语义不同，必须换键。
 func (o imageResizeOptions) resizeSourceKey(sourceID string, stat os.FileInfo) string {
 	h := sha256.New()
-	_, _ = fmt.Fprintf(h, "v2|%s", sourceID)
+	_, _ = fmt.Fprintf(h, "v3|%s", sourceID)
 	if stat != nil {
 		_, _ = fmt.Fprintf(h, "|%d|%d", stat.Size(), stat.ModTime().UnixNano())
 	}
@@ -356,13 +374,53 @@ func (p *ImageProxy) tryAcquireResizeSlot() (func(), bool) {
 	}
 }
 
-// acquireResizeSlotFor 对中等体积的图只尝试一次槽位。忙则放弃缩放，
-// 避免背景图墙在 2 核机器上排成数秒。超大原图仍等待，以免直出多兆字节。
+func (p *ImageProxy) resizeQueueTimeout() time.Duration {
+	if p != nil && p.resizeQueueWait > 0 {
+		return p.resizeQueueWait
+	}
+	return defaultResizeQueueWait
+}
+
+// acquireResizeSlotFor 对紧凑小图只尝试一次槽位，其余情况最多排队
+// resizeQueueTimeout。
+//
+// 从前这里对 1.5MB 以下的图一律「槽位忙就跳过缩放」，结果是并发加载海报墙
+// 时几乎每张图都回退成 1MB 上下的 PNG 原图：一页要传几十 MB，外部网络下单张
+// 图就要二十多秒。缩略图本身只有几十 KB，排队几百毫秒明显更划算；只有真正
+// 大到会拖慢页面的原图才值得在超时后直出。
 func (p *ImageProxy) acquireResizeSlotFor(ctx context.Context, size int64) (func(), bool) {
-	if size > 0 && size <= resizeQueueBypassBytes {
+	if size > 0 && size <= compactImageSkipBytes {
 		return p.tryAcquireResizeSlot()
 	}
-	return p.acquireResizeSlot(ctx)
+	return p.acquireResizeSlotWithin(ctx, p.resizeQueueTimeout())
+}
+
+// acquireResizeSlotWithin 在 timeout 内等待一格解码槽；超时或请求取消返回
+// false，调用方回退原图。
+func (p *ImageProxy) acquireResizeSlotWithin(ctx context.Context, timeout time.Duration) (func(), bool) {
+	if p == nil {
+		return func() {}, true
+	}
+	if timeout <= 0 {
+		return p.tryAcquireResizeSlot()
+	}
+	p.resizeSemMu.Lock()
+	if p.resizeSem == nil {
+		p.resizeSem = make(chan struct{}, imageResizeConcurrency())
+	}
+	sem := p.resizeSem
+	p.resizeSemMu.Unlock()
+
+	timer := time.NewTimer(timeout)
+	defer timer.Stop()
+	select {
+	case sem <- struct{}{}:
+		return func() { <-sem }, true
+	case <-timer.C:
+		return nil, false
+	case <-ctx.Done():
+		return nil, false
+	}
 }
 
 // serveResizedFromFile 从 srcPath 读取图片，按选项缩放后写出，并把结果缓存
@@ -472,10 +530,6 @@ func (p *ImageProxy) ensureResizeCache(ctx context.Context, srcPath string, o im
 // ponytail: 200KB 覆盖这台机器上的典型海报（平均约 100KB）；更大的图仍尝试缩放。
 const compactImageSkipBytes = 200 * 1024
 
-// resizeQueueBypassBytes 是“槽位忙就放弃缩放”的上限。超过它的原图继续排队，
-// 以免把未压缩的剧照直接发给客户端。
-const resizeQueueBypassBytes = 1536 * 1024
-
 // serveCompactOriginal 在源文件已经很小且是浏览器可直接显示的 JPEG/WebP 时
 // 跳过解码。返回 false 表示仍应走缩放路径。
 func serveCompactOriginal(w http.ResponseWriter, r *http.Request, srcPath string, stat os.FileInfo) bool {
@@ -504,6 +558,17 @@ func isCompactWebImage(header []byte) bool {
 		string(header[8:12]) == "WEBP"
 }
 
+// isCompactWebFormat 判断 image.DecodeConfig 报告的格式是否已经适合直接下发
+// 给浏览器。PNG/BMP/GIF 即使尺寸很小也可能有几百 KB，需要重编码成 JPEG。
+func isCompactWebFormat(format string) bool {
+	switch strings.ToLower(format) {
+	case "jpeg", "jpg", "webp":
+		return true
+	default:
+		return false
+	}
+}
+
 // writeResizeCache 原子写入缩放结果；失败只记日志，不影响本次响应。
 // 与 writeImageCache 一样不再持有全局锁：临时文件名唯一、rename 原子，
 // 持锁只会把缩略图的写盘和原图的写盘串成一条队。

internal/service/image_resize_test.go

@@ -123,17 +123,58 @@ func TestResizeImageDataScalesDownAndReencodesAsJPEG(t *testing.T) {
 	}
 }
 
-func TestResizeImageDataLeavesImagesWithinBoundsUntouched(t *testing.T) {
+// 尺寸已经在目标框内的 PNG 也必须转成 JPEG。刮削来的海报常是 1000×1500、
+// 1MB 级的 PNG；此前这种情况原样直出，一处海报墙就要下载几十 MB，外部网络下
+// 每张图要十几秒（线上实测单张 1.3MB / 20 多秒）。
+func TestResizeImageDataReencodesPNGWithinBounds(t *testing.T) {
 	data := encodeTestPNG(t, 200, 300, 255)
-	out, _, unchanged, err := resizeImageData(data, imageResizeOptions{MaxWidth: 400, MaxHeight: 600})
+	out, ctype, unchanged, err := resizeImageData(data, imageResizeOptions{MaxWidth: 400, MaxHeight: 600, Quality: 80})
+	if err != nil {
+		t.Fatalf("resize: %v", err)
+	}
+	if unchanged {
+		t.Fatal("PNG within the target box must still be re-encoded as a compact web format")
+	}
+	if ctype != "image/jpeg" {
+		t.Fatalf("content type = %q, want image/jpeg", ctype)
+	}
+	cfg, format, err := image.DecodeConfig(bytes.NewReader(out))
+	if err != nil {
+		t.Fatalf("decode re-encoded image: %v", err)
+	}
+	if format != "jpeg" {
+		t.Fatalf("format = %q, want jpeg", format)
+	}
+	if cfg.Width != 200 || cfg.Height != 300 {
+		t.Fatalf("re-encoded to %dx%d, want the original 200x300 (no upscaling)", cfg.Width, cfg.Height)
+	}
+}
+
+// 已经是紧凑 Web 格式且体积很小的源图仍然零成本直出。
+func TestResizeImageDataLeavesSmallCompactSourceUntouched(t *testing.T) {
+	var buf bytes.Buffer
+	img := image.NewRGBA(image.Rect(0, 0, 200, 300))
+	for y := 0; y < 300; y++ {
+		for x := 0; x < 200; x++ {
+			img.Set(x, y, color.RGBA{R: uint8(x % 16 * 16), G: uint8(y % 16 * 16), B: 200, A: 255})
+		}
+	}
+	if err := jpeg.Encode(&buf, img, &jpeg.Options{Quality: 80}); err != nil {
+		t.Fatalf("encode test jpeg: %v", err)
+	}
+	data := buf.Bytes()
+	if len(data) > compactImageSkipBytes {
+		t.Fatalf("test jpeg is %d bytes, expected a compact source", len(data))
+	}
+	out, ctype, unchanged, err := resizeImageData(data, imageResizeOptions{MaxWidth: 400, MaxHeight: 600})
 	if err != nil {
 		t.Fatalf("resize: %v", err)
 	}
 	if !unchanged {
-		t.Fatal("expected an image already within bounds to be returned unchanged")
+		t.Fatal("a compact JPEG already within bounds should be served unchanged")
 	}
-	if !bytes.Equal(out, data) {
-		t.Fatal("expected the original bytes to be returned verbatim")
+	if !bytes.Equal(out, data) || ctype != "image/jpeg" {
+		t.Fatalf("expected the original jpeg bytes back, got %d bytes of %q", len(out), ctype)
 	}
 }
 
@@ -302,7 +343,9 @@ func TestServeResizedFromFileSkipsDecodeForCompactJPEG(t *testing.T) {
 	}
 }
 
-func TestServeResizedFromFileDoesNotQueueWhenResizeBusy(t *testing.T) {
+// 排队上限：槽位一直不空时，请求最多等 resizeQueueWait，然后回退原图，
+// 不会被无限期挂住。这条约束保护的是请求本身，而不是「不等就直出原图」。
+func TestServeResizedFromFileFallsBackWhenResizeQueueStaysBusy(t *testing.T) {
 	dir := t.TempDir()
 	src := dir + string(os.PathSeparator) + "backdrop.jpg"
 	data := make([]byte, compactImageSkipBytes+1024)
@@ -310,7 +353,7 @@ func TestServeResizedFromFileDoesNotQueueWhenResizeBusy(t *testing.T) {
 	if err := os.WriteFile(src, data, 0o644); err != nil {
 		t.Fatalf("write source: %v", err)
 	}
-	proxy := &ImageProxy{cacheDir: dir + string(os.PathSeparator) + "cache"}
+	proxy := &ImageProxy{cacheDir: dir + string(os.PathSeparator) + "cache", resizeQueueWait: 50 * time.Millisecond}
 	var releases []func()
 	for i := 0; i < imageResizeConcurrency(); i++ {
 		release, ok := proxy.acquireResizeSlot(context.Background())
@@ -327,10 +370,77 @@ func TestServeResizedFromFileDoesNotQueueWhenResizeBusy(t *testing.T) {
 
 	start := time.Now()
 	handled := proxy.serveResizedFromFile(httptest.NewRecorder(), httptest.NewRequest("GET", "/x?maxWidth=480", nil), src, imageResizeOptions{MaxWidth: 480})
-	if time.Since(start) > 200*time.Millisecond {
-		t.Fatal("resize slot was busy but the request still waited in the queue")
+	if elapsed := time.Since(start); elapsed > 500*time.Millisecond {
+		t.Fatalf("request waited %v with every slot held; the queue wait must be bounded", elapsed)
 	}
 	if handled {
-		t.Fatal("expected a busy resize slot to fall back so the caller can serve the original")
+		t.Fatal("expected a permanently busy queue to fall back so the caller can serve the original")
+	}
+}
+
+// 槽位只是短暂忙碌时必须排队等待并产出缩略图，而不是直出多兆字节原图。
+// 这是线上「海报墙每张图 20 多秒」的根因：并发加载时槽位全忙，旧逻辑把
+// 1MB 级 PNG 原样下发。
+// encodeNoisyPNG 生成难以压缩的 PNG：规则色块会被压到 1KB 级别，测不出
+// 「大体积 PNG 被原样下发」这条回归。
+func encodeNoisyPNG(t *testing.T, w, h int) []byte {
+	t.Helper()
+	img := image.NewRGBA(image.Rect(0, 0, w, h))
+	seed := uint32(0x9e3779b9)
+	for y := 0; y < h; y++ {
+		for x := 0; x < w; x++ {
+			seed = seed*1664525 + 1013904223
+			img.Set(x, y, color.RGBA{R: uint8(seed >> 24), G: uint8(seed >> 16), B: uint8(seed >> 8), A: 255})
+		}
+	}
+	var buf bytes.Buffer
+	if err := png.Encode(&buf, img); err != nil {
+		t.Fatalf("encode noisy png: %v", err)
+	}
+	return buf.Bytes()
+}
+
+func TestServeResizedFromFileWaitsForSlotInsteadOfServingOriginal(t *testing.T) {
+	dir := t.TempDir()
+	src := dir + string(os.PathSeparator) + "poster.png"
+	original := encodeNoisyPNG(t, 378, 540)
+	if len(original) <= compactImageSkipBytes {
+		t.Fatalf("test poster is %d bytes, want a source above the compact threshold", len(original))
+	}
+	if err := os.WriteFile(src, original, 0o644); err != nil {
+		t.Fatalf("write source: %v", err)
+	}
+	proxy := &ImageProxy{cacheDir: dir + string(os.PathSeparator) + "cache"}
+	var releases []func()
+	for i := 0; i < imageResizeConcurrency(); i++ {
+		release, ok := proxy.acquireResizeSlot(context.Background())
+		if !ok {
+			t.Fatal("expected a resize slot")
+		}
+		releases = append(releases, release)
+	}
+	go func() {
+		time.Sleep(40 * time.Millisecond)
+		releases[0]()
+	}()
+
+	rec := httptest.NewRecorder()
+	if !proxy.serveResizedFromFile(rec, httptest.NewRequest("GET", "/x?maxWidth=480&maxHeight=600", nil), src, imageResizeOptions{MaxWidth: 480, MaxHeight: 600}) {
+		t.Fatal("expected the request to wait for the slot and serve a thumbnail")
+	}
+	body := rec.Body.Bytes()
+	if bytes.Equal(body, original) {
+		t.Fatal("served the multi-hundred-KB PNG original instead of a re-encoded thumbnail")
+	}
+	if rec.Header().Get("Content-Type") != "image/jpeg" {
+		t.Fatalf("content type = %q, want image/jpeg", rec.Header().Get("Content-Type"))
+	}
+	// 同一请求第二次必须直接命中缩放缓存。
+	rec2 := httptest.NewRecorder()
+	if !proxy.serveResizedFromFile(rec2, httptest.NewRequest("GET", "/x?maxWidth=480&maxHeight=600", nil), src, imageResizeOptions{MaxWidth: 480, MaxHeight: 600}) {
+		t.Fatal("expected the cached thumbnail to be reused")
+	}
+	if !bytes.Equal(rec2.Body.Bytes(), body) {
+		t.Fatal("expected the cached thumbnail bytes to be identical")
 	}
 }

internal/service/introdb.go

@@ -22,8 +22,9 @@ import (
 
 const (
 	// IntroDBBaseURL is the public read endpoint. Overridable on the service
-	// for tests and for pointing at a mirror.
-	IntroDBBaseURL = "https://api.theintrodb.org/v3"
+	// for tests and for pointing at a mirror. v1 已删除，v2/v3 冻结在只读的
+	// GET /media 上并被官方标记为弃用，所以这里直接跟 v4。
+	IntroDBBaseURL = "https://api.theintrodb.org/v4"
 	// IntroDBSource tags rows that came from this provider.
 	IntroDBSource = "theintrodb"
 
@@ -92,8 +93,10 @@ type introDBRange struct {
 	EndMs   *int64 `json:"end_ms"`
 }
 
+// introDBResponse 对应 v4 的 MediaResponse。v4 以 TVDB 为身份，响应只带
+// tvdb_id —— tmdb_id 字段已被官方移除，需要 tmdb_id 只能从请求侧自己记。
 type introDBResponse struct {
-	TMDbID  int            `json:"tmdb_id"`
+	TVDBID  int            `json:"tvdb_id"`
 	Type    string         `json:"type"`
 	Intro   []introDBRange `json:"intro"`
 	Recap   []introDBRange `json:"recap"`

internal/service/introdb_test.go

@@ -11,11 +11,12 @@ import (
 	"go.uber.org/zap"
 )
 
-// 这两段响应是从 api.theintrodb.org/v3/media 实测抓下来的原文，
-// 用来锁住 null 语义：start_ms: null = 从片头开始，end_ms: null = 一直到片尾。
+// 这两段响应是从 api.theintrodb.org/v4/media 实测抓下来的原文（v4 以 TVDB 为身份，
+// 响应里只有 tvdb_id），用来锁住 null 语义：start_ms: null = 从片头开始，
+// end_ms: null = 一直到片尾。
 const (
-	introDBTVPayload    = `{"tmdb_id":1396,"type":"tv","season":1,"episode":1,"intro":[{"start_ms":228664,"end_ms":246143}],"credits":[{"start_ms":3431000,"end_ms":null}]}`
-	introDBMoviePayload = `{"tmdb_id":27205,"type":"movie","intro":[{"start_ms":null,"end_ms":38000}]}`
+	introDBTVPayload    = `{"tvdb_id":81189,"type":"tv","season":1,"episode":1,"intro":[{"start_ms":228664,"end_ms":246143}],"credits":[{"start_ms":3431000,"end_ms":null}]}`
+	introDBMoviePayload = `{"tvdb_id":113,"type":"movie","intro":[{"start_ms":null,"end_ms":38000}]}`
 )
 
 func TestParseIntroDBResponseResolvesNullBounds(t *testing.T) {
@@ -48,7 +49,7 @@ func TestParseIntroDBResponseResolvesNullBounds(t *testing.T) {
 }
 
 func TestParseIntroDBResponseDropsEmptyRanges(t *testing.T) {
-	body := `{"tmdb_id":1,"type":"movie",
+	body := `{"tvdb_id":1,"type":"movie",
 		"intro":[{"start_ms":5000,"end_ms":5000},{"start_ms":9000,"end_ms":8000},{"start_ms":1000,"end_ms":2000}],
 		"recap":[],"credits":[],"preview":[]}`
 	spans, err := parseIntroDBResponse([]byte(body))
@@ -62,7 +63,7 @@ func TestParseIntroDBResponseDropsEmptyRanges(t *testing.T) {
 }
 
 func TestParseIntroDBResponseOrdersByType(t *testing.T) {
-	body := `{"tmdb_id":1,"type":"tv","credits":[{"start_ms":900,"end_ms":1000}],
+	body := `{"tvdb_id":1,"type":"tv","credits":[{"start_ms":900,"end_ms":1000}],
 		"intro":[{"start_ms":100,"end_ms":200}],"recap":[{"start_ms":50,"end_ms":60}]}`
 	spans, err := parseIntroDBResponse([]byte(body))
 	if err != nil {
@@ -82,12 +83,12 @@ func TestParseIntroDBResponseOrdersByType(t *testing.T) {
 func TestIntroDBMediaURLOnlyAddsSeasonEpisodeForTV(t *testing.T) {
 	svc := NewIntroDBService(zap.NewNop())
 	if got, want := svc.mediaURL(1396, 1, 1),
-		"https://api.theintrodb.org/v3/media?tmdb_id=1396&season=1&episode=1"; got != want {
+		"https://api.theintrodb.org/v4/media?tmdb_id=1396&season=1&episode=1"; got != want {
 		t.Fatalf("tv url = %q, want %q", got, want)
 	}
 	// 电影（season/episode 为 0）不能带季集参数，否则会被当成剧集查不到。
 	if got, want := svc.mediaURL(27205, 0, 0),
-		"https://api.theintrodb.org/v3/media?tmdb_id=27205"; got != want {
+		"https://api.theintrodb.org/v4/media?tmdb_id=27205"; got != want {
 		t.Fatalf("movie url = %q, want %q", got, want)
 	}
 }

internal/service/local_metadata_adult_test.go

@@ -184,6 +184,85 @@ func TestReadAdultMetadataDerivesDMMPosterFromRemoteFanart(t *testing.T) {
 	}
 }
 
+func TestReadAdultArtworkIgnoresLoosePosterInLibraryRoot(t *testing.T) {
+	root := t.TempDir()
+	// 云下载这类库把不同影片平铺在同一个根目录里，根目录中残留的松散海报
+	// 属于别的影片，不能被抓来当作当前影片的封面。
+	if err := os.WriteFile(filepath.Join(root, "AAA-001-poster.jpg"), []byte("jpg"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(root, "AAA-001-fanart.jpg"), []byte("jpg"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	mediaPath := filepath.Join(root, "BBB-002.mp4")
+	if err := os.WriteFile(mediaPath, []byte("x"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := ReadLocalMetadata(mediaPath, root, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != nil && (got.PosterURL != "" || got.BackdropURL != "") {
+		t.Fatalf("library-root artwork must not be inherited: poster=%q backdrop=%q", got.PosterURL, got.BackdropURL)
+	}
+}
+
+func TestReadAdultArtworkIgnoresLoosePosterInSharedFolder(t *testing.T) {
+	root := t.TempDir()
+	dir := filepath.Join(root, "shared")
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	for _, name := range []string{"AAA-001.mp4", "BBB-002.mp4"} {
+		if err := os.WriteFile(filepath.Join(dir, name), []byte("x"), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if err := os.WriteFile(filepath.Join(dir, "AAA-001-poster.jpg"), []byte("jpg"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(dir, "AAA-001-fanart.jpg"), []byte("jpg"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := ReadLocalMetadata(filepath.Join(dir, "BBB-002.mp4"), root, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != nil && (got.PosterURL != "" || got.BackdropURL != "") {
+		t.Fatalf("sibling artwork must not be inherited in a shared folder: poster=%q backdrop=%q", got.PosterURL, got.BackdropURL)
+	}
+}
+
+func TestReadAdultArtworkKeepsLooseFallbackInItemFolder(t *testing.T) {
+	root := t.TempDir()
+	dir := filepath.Join(root, "BBB-002")
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	mediaPath := filepath.Join(dir, "video.mp4")
+	if err := os.WriteFile(mediaPath, []byte("x"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	poster := filepath.Join(dir, "japanese-title-cover.jpg")
+	fanart := filepath.Join(dir, "japanese-title-fanart.jpg")
+	if err := os.WriteFile(poster, []byte("jpg"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(fanart, []byte("jpg"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := ReadLocalMetadata(mediaPath, root, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got == nil || got.PosterURL != poster || got.BackdropURL != fanart {
+		t.Fatalf("single-item folder should keep loose artwork fallback: %+v", got)
+	}
+}
+
 func TestReadAdultArtworkByCodeWithoutNFO(t *testing.T) {
 	root := t.TempDir()
 	mediaPath := filepath.Join(root, "SSIS-001-CD1.mp4")

internal/service/local_metadata_artwork.go

@@ -11,23 +11,23 @@ import (
 	"strings"
 )
 
-func metadataFromArtwork(mediaPath, showBaseDir string) *LocalMetadata {
+func metadataFromArtwork(mediaPath, showBaseDir, libraryRoot string) *LocalMetadata {
 	meta := &LocalMetadata{}
-	mergeArtworkMetadata(meta, mediaPath, showBaseDir)
+	mergeArtworkMetadata(meta, mediaPath, showBaseDir, libraryRoot)
 	if meta.PosterURL == "" && meta.BackdropURL == "" {
 		return nil
 	}
 	return meta
 }
 
-func mergeArtworkMetadata(meta *LocalMetadata, mediaPath, showBaseDir string) {
+func mergeArtworkMetadata(meta *LocalMetadata, mediaPath, showBaseDir, libraryRoot string) {
 	if meta == nil {
 		return
 	}
 	mediaDir := filepath.Dir(mediaPath)
 	if localPoster := firstLocalPoster(mediaPath, showBaseDir); localPoster != "" {
 		meta.PosterURL = localPoster
-	} else if meta.PosterURL == "" {
+	} else if meta.PosterURL == "" && looseArtworkFallbackAllowed(mediaDir, libraryRoot) {
 		meta.PosterURL = firstAdultLooseImage(mediaDir, "poster")
 	}
 	dirs := []string{mediaDir, showBaseDir}
@@ -39,7 +39,7 @@ func mergeArtworkMetadata(meta *LocalMetadata, mediaPath, showBaseDir string) {
 			meta.BackdropURL = img
 			break
 		}
-		if meta.BackdropURL == "" {
+		if meta.BackdropURL == "" && looseArtworkFallbackAllowed(dir, libraryRoot) {
 			meta.BackdropURL = firstAdultLooseImage(dir, "backdrop")
 		}
 	}
@@ -245,6 +245,48 @@ func firstExistingPosterImage(dir string, names ...string) string {
 	return ""
 }
 
+// looseArtworkFallbackAllowed reports whether an unmatched image sitting in dir
+// can be attributed to mediaPath. Such an image carries no filename relation to
+// a specific video, so it is only trustworthy when the folder holds a single
+// media file and that folder is not the library root. Download tools routinely
+// drop unrelated titles flat into one directory (a 115 cloud-download library,
+// for example); claiming the first "*-poster.jpg" there made every item show the
+// same artwork. Mirrors the root-level guard findMovieNFO already applies to
+// loose NFO files.
+func looseArtworkFallbackAllowed(dir, libraryRoot string) bool {
+	if dir == "" {
+		return false
+	}
+	if libraryRoot != "" && samePath(dir, libraryRoot) {
+		return false
+	}
+	return countMediaFilesInDir(dir) <= 1
+}
+
+// countMediaFilesInDir counts the video files directly inside dir, stopping once
+// more than one is found. It walks the real directory rather than reusing the
+// loose-image glob because a shared folder may contain no images at all.
+func countMediaFilesInDir(dir string) int {
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		return 0
+	}
+	count := 0
+	for _, entry := range entries {
+		if entry.IsDir() {
+			continue
+		}
+		if _, ok := videoExtensions[strings.ToLower(filepath.Ext(entry.Name()))]; !ok {
+			continue
+		}
+		count++
+		if count > 1 {
+			return count
+		}
+	}
+	return count
+}
+
 func firstAdultLooseImage(dir, kind string) string {
 	if dir == "" {
 		return ""

internal/service/local_metadata_read.go

@@ -17,12 +17,12 @@ func ReadLocalMetadata(mediaPath, libraryRoot string, seriesLike bool) (*LocalMe
 	doc, path, err := findMovieNFO(mediaPath, libraryRoot)
 	if err != nil {
 		if errors.Is(err, os.ErrNotExist) {
-			return metadataFromArtwork(mediaPath, ""), nil
+			return metadataFromArtwork(mediaPath, "", libraryRoot), nil
 		}
 		return nil, err
 	}
 	meta := metadataFromDoc(doc, filepath.Dir(path), false)
-	mergeArtworkMetadata(meta, mediaPath, filepath.Dir(path))
+	mergeArtworkMetadata(meta, mediaPath, filepath.Dir(path), libraryRoot)
 	// A sidecar written while resolution tokens were misread as SxxExx must not
 	// reintroduce the bogus season/episode on rescan.
 	dropResolutionArtifactEpisodeIdentity(meta, mediaPath)
@@ -115,9 +115,9 @@ func readSeriesMetadata(mediaPath, libraryRoot string) (*LocalMetadata, error) {
 		}
 	}
 	if meta == nil {
-		meta = metadataFromArtwork(mediaPath, showBaseDir)
+		meta = metadataFromArtwork(mediaPath, showBaseDir, libraryRoot)
 	} else {
-		mergeArtworkMetadata(meta, mediaPath, showBaseDir)
+		mergeArtworkMetadata(meta, mediaPath, showBaseDir, libraryRoot)
 	}
 	// A sidecar written while resolution tokens were misread as SxxExx must not
 	// reintroduce the bogus season/episode on rescan.

internal/service/media.go

@@ -12,13 +12,14 @@ import (
 
 // MediaService offers high-level CRUD over libraries and media items.
 type MediaService struct {
-	cfg                 *config.Config
-	log                 *zap.Logger
-	repo                *repository.Container
-	cache               *RuntimeCacheService
-	groupedMediaFlight  singleflight.Group
-	libraryRowsFlight   singleflight.Group
-	recentSeriesFlight  singleflight.Group
+	cfg                *config.Config
+	log                *zap.Logger
+	repo               *repository.Container
+	cache              *RuntimeCacheService
+	groupedMediaFlight singleflight.Group
+	mediaSortFlight    singleflight.Group
+	libraryRowsFlight  singleflight.Group
+	recentSeriesFlight singleflight.Group
 }
 
 type MediaVisibility struct {

internal/service/media_listing.go

@@ -5,7 +5,7 @@ import (
 	"strings"
 	"time"
 
-	"go.uber.org/zap"
+	"github.com/google/uuid"
 
 	"github.com/truewhile/MeBox/internal/model"
 	"github.com/truewhile/MeBox/internal/repository"
@@ -129,6 +129,26 @@ func (s *MediaService) GroupedMediaVisibleFiltered(
 	visibility MediaVisibility,
 	filters MediaListFilters,
 ) ([]MediaItem, error) {
+	value, err := s.groupedMediaVisibleFiltered(ctx, libraryID, visibility, filters)
+	if err != nil {
+		return nil, err
+	}
+	return value.Items, nil
+}
+
+// Each immutable grouping has its own revision. Lightweight sort indices can
+// reference that revision without retaining another copy of the full rows.
+type groupedMediaCacheValue struct {
+	Items    []MediaItem
+	Revision string
+}
+
+func (s *MediaService) groupedMediaVisibleFiltered(
+	ctx context.Context,
+	libraryID string,
+	visibility MediaVisibility,
+	filters MediaListFilters,
+) (*groupedMediaCacheValue, error) {
 	visibility = ExpandMediaVisibilityForMergedCloudLibraries(ctx, s.repo, visibility)
 	libraryIDs, err := MergedLibraryIDsForLibrary(ctx, s.repo, libraryID)
 	if err != nil {
@@ -143,7 +163,7 @@ func (s *MediaService) GroupedMediaVisibleFiltered(
 	value, err, _ := s.groupedMediaFlight.Do(itemsCacheKey, func() (any, error) {
 		if s.cache != nil {
 			if cachedObj, ok := s.cache.GetObject(itemsCacheKey); ok {
-				if cached, ok := cachedObj.([]MediaItem); ok {
+				if cached, ok := cachedObj.(*groupedMediaCacheValue); ok {
 					return cached, nil
 				}
 			}
@@ -154,8 +174,8 @@ func (s *MediaService) GroupedMediaVisibleFiltered(
 		if err != nil {
 			return nil, err
 		}
-		grouped := groupMediaVersions(items)
-		if s.cache != nil && len(grouped) > 0 {
+		grouped := &groupedMediaCacheValue{Items: groupMediaVersions(items), Revision: uuid.NewString()}
+		if s.cache != nil && len(grouped.Items) > 0 {
 			s.cache.SetObject(itemsCacheKey, grouped, s.mediaObjectTTL())
 		}
 		return grouped, nil
@@ -163,10 +183,10 @@ func (s *MediaService) GroupedMediaVisibleFiltered(
 	if err != nil {
 		return nil, err
 	}
-	if grouped, ok := value.([]MediaItem); ok {
+	if grouped, ok := value.(*groupedMediaCacheValue); ok {
 		return grouped, nil
 	}
-	return nil, nil
+	return &groupedMediaCacheValue{}, nil
 }
 
 func (s *MediaService) listMediaVisibleForGrouping(ctx context.Context, libraryID string, visibility MediaVisibility, filters MediaListFilters) ([]model.Media, error) {
@@ -180,24 +200,19 @@ func (s *MediaService) listMediaVisibleForGrouping(ctx context.Context, libraryI
 		AllowedLibraryIDs: visibility.AllowedLibraryIDs,
 		HiddenLibraryIDs:  visibility.HiddenLibraryIDs,
 	})
-	// 版本分组的 URL 分页发生在 Go 进程内，响应里的 total 是分组后的数量，
-	// 不需要数据库再为原始行做一次 COUNT(*)。全量 COUNT 在超大媒体库上
-	// 会重复扫描整个 library_id 范围，而这里只关心是否存在截断风险。
-	items, err := s.repo.Media.ListByLibrariesFilteredNoCount(ctx, libraryIDs, 0, maxMediaSearchLimit, filter)
+	// Group before paginating so versions stay together. The search safety limit
+	// must not truncate a library listing or its reported grouped total.
+	items, err := s.repo.Media.ListAllByLibrariesFilteredNoCount(ctx, libraryIDs, filter)
 	if err != nil {
 		return nil, err
 	}
-	if len(items) >= maxMediaSearchLimit && s.log != nil {
-		s.log.Warn("media version grouping may be truncated by safety limit",
-			zap.String("library_id", libraryID),
-			zap.Int("limit", maxMediaSearchLimit))
-	}
 	s.attachLibraryMetadata(ctx, items)
 	return items, nil
 }
 
 // GetMedia returns a single media row.
-func (s *MediaService) GetMedia(ctx context.Context, id string) (*model.Media, error) {	media, err := s.repo.Media.FindByID(ctx, id)
+func (s *MediaService) GetMedia(ctx context.Context, id string) (*model.Media, error) {
+	media, err := s.repo.Media.FindByID(ctx, id)
 	if err != nil || media == nil {
 		return media, err
 	}

internal/service/media_search.go

@@ -2,17 +2,71 @@ package service
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/truewhile/MeBox/internal/model"
 	"github.com/truewhile/MeBox/internal/repository"
 )
 
+type MediaQualityItem struct {
+	Issue string      `json:"issue"`
+	Media model.Media `json:"media"`
+}
+
+func (s *MediaService) QualityIssues(ctx context.Context, issue string, page, pageSize int) ([]MediaQualityItem, int64, error) {
+	if page < 1 {
+		page = 1
+	}
+	if pageSize < 1 {
+		pageSize = 50
+	}
+	if pageSize > 100 {
+		pageSize = 100
+	}
+	q := s.repo.DB.WithContext(ctx).Model(&model.Media{})
+	switch issue {
+	case "missing":
+		q = q.Where("availability_state = ?", "missing")
+	case "unmatched":
+		q = q.Where("scrape_status IN ? OR scrape_status = ''", []string{"pending", "no_match"})
+	case "poster":
+		q = q.Where("poster_url IS NULL OR TRIM(poster_url) = ''")
+	default:
+		return nil, 0, fmt.Errorf("unknown quality issue: %s", issue)
+	}
+	var total int64
+	if err := q.Count(&total).Error; err != nil {
+		return nil, 0, err
+	}
+	var rows []model.Media
+	if err := q.Order("updated_at DESC, id ASC").Offset((page - 1) * pageSize).Limit(pageSize).Find(&rows).Error; err != nil {
+		return nil, 0, err
+	}
+	s.attachLibraryMetadata(ctx, rows)
+	items := make([]MediaQualityItem, 0, len(rows))
+	for _, media := range rows {
+		items = append(items, MediaQualityItem{Issue: issue, Media: media})
+	}
+	return items, total, nil
+}
+
+type MediaSearchFilter struct {
+	LibraryID string
+	YearMin   int
+	YearMax   int
+	Genres    []string
+}
+
 // SearchMedia performs a simple LIKE search across titles.
 func (s *MediaService) SearchMedia(ctx context.Context, query string, limit int) ([]model.Media, error) {
 	return s.SearchMediaVisible(ctx, query, limit, MediaVisibility{IncludeNSFW: true})
 }
 
 func (s *MediaService) SearchMediaVisible(ctx context.Context, query string, limit int, visibility MediaVisibility) ([]model.Media, error) {
+	return s.SearchMediaVisibleFiltered(ctx, query, limit, visibility, MediaSearchFilter{})
+}
+
+func (s *MediaService) SearchMediaVisibleFiltered(ctx context.Context, query string, limit int, visibility MediaVisibility, filter MediaSearchFilter) ([]model.Media, error) {
 	if limit <= 0 {
 		limit = 50
 	} else if limit > maxMediaSearchLimit {
@@ -23,6 +77,10 @@ func (s *MediaService) SearchMediaVisible(ctx context.Context, query string, lim
 		IncludeNSFW:       visibility.IncludeNSFW,
 		AllowedLibraryIDs: visibility.AllowedLibraryIDs,
 		HiddenLibraryIDs:  visibility.HiddenLibraryIDs,
+		LibraryID:         filter.LibraryID,
+		YearMin:           filter.YearMin,
+		YearMax:           filter.YearMax,
+		Genres:            filter.Genres,
 	})
 	if err != nil {
 		return nil, err
@@ -45,6 +103,10 @@ func (s *MediaService) SearchMediaVisibleGrouped(ctx context.Context, query stri
 }
 
 func (s *MediaService) SearchMediaVisiblePage(ctx context.Context, query string, page, pageSize int, visibility MediaVisibility) ([]model.Media, int64, error) {
+	return s.SearchMediaVisiblePageFiltered(ctx, query, page, pageSize, visibility, MediaSearchFilter{})
+}
+
+func (s *MediaService) SearchMediaVisiblePageFiltered(ctx context.Context, query string, page, pageSize int, visibility MediaVisibility, filter MediaSearchFilter) ([]model.Media, int64, error) {
 	if pageSize <= 0 {
 		pageSize = 50
 	}
@@ -59,6 +121,10 @@ func (s *MediaService) SearchMediaVisiblePage(ctx context.Context, query string,
 		IncludeNSFW:       visibility.IncludeNSFW,
 		AllowedLibraryIDs: visibility.AllowedLibraryIDs,
 		HiddenLibraryIDs:  visibility.HiddenLibraryIDs,
+		LibraryID:         filter.LibraryID,
+		YearMin:           filter.YearMin,
+		YearMax:           filter.YearMax,
+		Genres:            filter.Genres,
 	})
 	if err != nil {
 		return nil, 0, err

internal/service/media_sorted_page.go

@@ -0,0 +1,77 @@
+package service
+
+import (
+	"context"
+	"fmt"
+	"sort"
+	"time"
+)
+
+// ListMediaVisibleSortedPage reuses grouped rows and a small position index.
+// Only the requested page is copied; pagination does not sort the full library
+// again or retain a second full-size MediaItem slice for every sort order.
+func (s *MediaService) ListMediaVisibleSortedPage(
+	ctx context.Context,
+	libraryID string,
+	page, pageSize int,
+	visibility MediaVisibility,
+	filters MediaListFilters,
+	spec MediaSortSpec,
+	history map[string]time.Time,
+) ([]MediaItem, int64, error) {
+	grouped, err := s.groupedMediaVisibleFiltered(ctx, libraryID, visibility, filters)
+	if err != nil {
+		return nil, 0, err
+	}
+	spec = NormalizeMediaSort(spec.Field, spec.Order)
+	indices := s.sortedMediaIndices(grouped, spec, history)
+	page, pageSize = normalizeGroupedMediaPage(page, pageSize)
+	total := len(grouped.Items)
+	// Division avoids overflowing (page-1)*pageSize on an excessive page value.
+	if total == 0 || page-1 > (total-1)/pageSize {
+		return []MediaItem{}, int64(total), nil
+	}
+	start := (page - 1) * pageSize
+	end := min(start+pageSize, total)
+	items := make([]MediaItem, 0, end-start)
+	for _, index := range indices[start:end] {
+		items = append(items, grouped.Items[index])
+	}
+	return items, int64(total), nil
+}
+
+func (s *MediaService) sortedMediaIndices(grouped *groupedMediaCacheValue, spec MediaSortSpec, history map[string]time.Time) []int {
+	// Playback history changes independently of the media cache and is personal.
+	// Keep this explicit sort live rather than caching another user's history.
+	if s.cache == nil || spec.Field == "last_played" || len(grouped.Items) == 0 {
+		return sortMediaIndices(grouped.Items, spec, history)
+	}
+	key := fmt.Sprintf("media:obj:sort:%s:%s:%s", grouped.Revision, spec.Field, spec.Order)
+	value, _, _ := s.mediaSortFlight.Do(key, func() (any, error) {
+		if cached, ok := s.cache.GetObject(key); ok {
+			if indices, ok := cached.([]int); ok {
+				return indices, nil
+			}
+		}
+		indices := sortMediaIndices(grouped.Items, spec, history)
+		s.cache.SetObject(key, indices, s.mediaObjectTTL())
+		return indices, nil
+	})
+	return value.([]int)
+}
+
+func sortMediaIndices(items []MediaItem, spec MediaSortSpec, history map[string]time.Time) []int {
+	indices := make([]int, len(items))
+	for i := range indices {
+		indices[i] = i
+	}
+	sort.SliceStable(indices, func(i, j int) bool {
+		a, b := items[indices[i]], items[indices[j]]
+		cmp := compareMediaByField(a, b, spec, history)
+		if cmp == 0 {
+			cmp = compareID(a.ID, b.ID)
+		}
+		return cmp < 0
+	})
+	return indices
+}

internal/service/media_sorted_page_test.go

@@ -0,0 +1,141 @@
+package service
+
+import (
+	"fmt"
+	"math"
+	"testing"
+	"time"
+
+	"go.uber.org/zap"
+
+	"github.com/truewhile/MeBox/internal/config"
+	"github.com/truewhile/MeBox/internal/model"
+	"github.com/truewhile/MeBox/internal/repository"
+)
+
+func TestSortedMediaPageIncludesRowsBeyondSearchLimit(t *testing.T) {
+	db := newServiceTestDB(t)
+	repos := repository.New(db)
+	lib := model.Library{Name: "Large", Path: "/media/large", Type: "movie", Enabled: true}
+	if err := repos.Library.Create(t.Context(), &lib); err != nil {
+		t.Fatal(err)
+	}
+	// This must cross the historical 50,000-row boundary: a smaller fixture
+	// cannot detect truncation before grouping, counting, and sorting.
+	now := time.Now()
+	for start := 0; start <= maxMediaSearchLimit; start += 500 {
+		var rows []model.Media
+		for i := start; i < min(start+500, maxMediaSearchLimit+1); i++ {
+			rows = append(rows, model.Media{
+				Base:      model.Base{ID: fmt.Sprintf("large-%05d", i), CreatedAt: now, UpdatedAt: now},
+				LibraryID: lib.ID, Path: fmt.Sprintf("/media/large/%05d.mkv", i),
+				Title: fmt.Sprintf("Movie %05d", i), TMDbID: i + 1,
+			})
+		}
+		if err := db.CreateInBatches(&rows, 100).Error; err != nil {
+			t.Fatal(err)
+		}
+	}
+	svc := NewMediaService(&config.Config{}, zap.NewNop(), repos)
+	items, total, err := svc.ListMediaVisibleSortedPage(t.Context(), lib.ID, maxMediaSearchLimit/100+1, 100,
+		MediaVisibility{IncludeNSFW: true}, MediaListFilters{}, MediaSortSpec{Field: "title", Order: "asc"}, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if total != int64(maxMediaSearchLimit+1) || len(items) != 1 || items[0].ID != "large-50000" {
+		t.Fatalf("total=%d, page length=%d, want 50001 rows and final item large-50000", total, len(items))
+	}
+}
+
+func TestSortedMediaPagesReuseIndicesAndRefreshAfterInvalidation(t *testing.T) {
+	db := newServiceTestDB(t)
+	repos := repository.New(db)
+	lib := model.Library{Name: "Movies", Path: "/media/movies", Type: "movie", Enabled: true}
+	if err := repos.Library.Create(t.Context(), &lib); err != nil {
+		t.Fatal(err)
+	}
+	rows := []model.Media{
+		{Base: model.Base{ID: "alpha"}, LibraryID: lib.ID, Path: "/media/movies/a.mkv", Title: "Alpha", TMDbID: 1, SizeBytes: 100},
+		{Base: model.Base{ID: "alpha-alt"}, LibraryID: lib.ID, Path: "/media/movies/a-alt.mkv", Title: "Alpha", TMDbID: 1, SizeBytes: 50},
+		{Base: model.Base{ID: "beta"}, LibraryID: lib.ID, Path: "/media/movies/b.mkv", Title: "Beta", TMDbID: 2},
+		{Base: model.Base{ID: "hidden"}, LibraryID: lib.ID, Path: "/media/movies/hidden.mkv", Title: "Hidden", TMDbID: 3, NSFW: true},
+	}
+	if err := db.Create(&rows).Error; err != nil {
+		t.Fatal(err)
+	}
+	svc := NewMediaService(&config.Config{}, zap.NewNop(), repos).
+		SetRuntimeCache(NewRuntimeCacheService(&config.Config{}, zap.NewNop()))
+	visibility := MediaVisibility{IncludeNSFW: false}
+	spec := MediaSortSpec{Field: "title", Order: "asc"}
+	first, total, err := svc.ListMediaVisibleSortedPage(t.Context(), lib.ID, 1, 1, visibility, MediaListFilters{}, spec, nil)
+	if err != nil || total != 2 || len(first) != 1 || first[0].ID != "alpha" || len(first[0].Versions) != 2 {
+		t.Fatalf("first=%#v, total=%d, error=%v", first, total, err)
+	}
+	grouped, err := svc.groupedMediaVisibleFiltered(t.Context(), lib.ID, visibility, MediaListFilters{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	index := svc.sortedMediaIndices(grouped, spec, nil)
+	second, _, err := svc.ListMediaVisibleSortedPage(t.Context(), lib.ID, 2, 1, visibility, MediaListFilters{}, spec, nil)
+	if err != nil || len(second) != 1 || second[0].ID != "beta" {
+		t.Fatalf("second=%#v, error=%v", second, err)
+	}
+	cachedIndex := svc.sortedMediaIndices(grouped, spec, nil)
+	if &index[0] != &cachedIndex[0] {
+		t.Fatal("pagination rebuilt the sorted position index")
+	}
+	// The returned page is independently writable without corrupting cached rows.
+	first[0].Title = "Modified by caller"
+	if err := db.Model(&model.Media{}).Where("id = ?", "beta").Update("title", "Aardvark").Error; err != nil {
+		t.Fatal(err)
+	}
+	svc.invalidateMediaCache(t.Context())
+	fresh, _, err := svc.ListMediaVisibleSortedPage(t.Context(), lib.ID, 1, 1, visibility, MediaListFilters{}, spec, nil)
+	if err != nil || len(fresh) != 1 || fresh[0].ID != "beta" {
+		t.Fatalf("updated page=%#v, error=%v", fresh, err)
+	}
+	empty, _, err := svc.ListMediaVisibleSortedPage(t.Context(), lib.ID, math.MaxInt, 100, visibility, MediaListFilters{}, spec, nil)
+	if err != nil || empty == nil || len(empty) != 0 {
+		t.Fatalf("out-of-range page=%#v, error=%v", empty, err)
+	}
+}
+
+func TestMediaSortIndexDoesNotCachePersonalPlaybackHistory(t *testing.T) {
+	svc := NewMediaService(&config.Config{}, zap.NewNop(), nil).
+		SetRuntimeCache(NewRuntimeCacheService(&config.Config{}, zap.NewNop()))
+	grouped := &groupedMediaCacheValue{Revision: "history-test", Items: []MediaItem{
+		{Media: model.Media{Base: model.Base{ID: "a"}}},
+		{Media: model.Media{Base: model.Base{ID: "b"}}},
+	}}
+	spec := MediaSortSpec{Field: "last_played", Order: "desc"}
+	first := svc.sortedMediaIndices(grouped, spec, map[string]time.Time{"a": time.Now()})
+	second := svc.sortedMediaIndices(grouped, spec, map[string]time.Time{"b": time.Now()})
+	if first[0] != 0 || second[0] != 1 {
+		t.Fatalf("history sorts = %v, %v", first, second)
+	}
+}
+
+func BenchmarkMediaSortIndex(b *testing.B) {
+	items := make([]MediaItem, 10000)
+	for i := range items {
+		items[i].ID = fmt.Sprint(i)
+		items[i].Title = fmt.Sprintf("Movie %05d", len(items)-i)
+	}
+	spec := MediaSortSpec{Field: "title", Order: "asc"}
+	b.Run("sort-every-page", func(b *testing.B) {
+		b.ReportAllocs()
+		for b.Loop() {
+			SortMediaItems(items, spec.Field, spec.Order, nil)
+		}
+	})
+	b.Run("cached-position-index", func(b *testing.B) {
+		svc := NewMediaService(&config.Config{}, zap.NewNop(), nil).
+			SetRuntimeCache(NewRuntimeCacheService(&config.Config{}, zap.NewNop()))
+		grouped := &groupedMediaCacheValue{Items: items, Revision: "benchmark"}
+		svc.sortedMediaIndices(grouped, spec, nil)
+		b.ReportAllocs()
+		for b.Loop() {
+			svc.sortedMediaIndices(grouped, spec, nil)
+		}
+	})
+}

internal/service/scanner.go

@@ -14,6 +14,7 @@ import (
 	"errors"
 	"strings"
 	"sync"
+	"time"
 
 	"go.uber.org/zap"
 
@@ -144,32 +145,34 @@ type localMediaProbeTask struct {
 }
 
 type existingLocalMedia struct {
-	LibraryRootID string
-	RelativePath  string
-	Title         string
-	OriginalName  string
-	EpisodeTitle  string
-	SizeBytes     int64
-	DurationSec   int
-	Width         int
-	Height        int
-	VideoCodec    string
-	AudioCodec    string
-	Container     string
-	STRMURL       string
-	FileID        string
-	PosterURL     string
-	BackdropURL   string
-	Overview      string
-	Year          int
-	ReleaseDate   string
-	Rating        float32
-	TMDbID        int
-	BangumiID     int
-	DoubanID      string
-	TheTVDBID     string
-	SeasonNum     int
-	EpisodeNum    int
+	AvailabilityState string
+	MissingSince      *time.Time
+	LibraryRootID     string
+	RelativePath      string
+	Title             string
+	OriginalName      string
+	EpisodeTitle      string
+	SizeBytes         int64
+	DurationSec       int
+	Width             int
+	Height            int
+	VideoCodec        string
+	AudioCodec        string
+	Container         string
+	STRMURL           string
+	FileID            string
+	PosterURL         string
+	BackdropURL       string
+	Overview          string
+	Year              int
+	ReleaseDate       string
+	Rating            float32
+	TMDbID            int
+	BangumiID         int
+	DoubanID          string
+	TheTVDBID         string
+	SeasonNum         int
+	EpisodeNum        int
 	// EpisodeFraction 是集号的小数部分（S01E11.5 → 0.5）；变化同样要触发刷新，
 	// 否则已有行上的「半集」标记不会被写回。
 	EpisodeFraction float64

internal/service/scanner_existing_media.go

@@ -33,7 +33,7 @@ func (s *ScannerService) existingLocalMediaSnapshotForRoot(ctx context.Context,
 		query = query.Where("(library_root_id = ? OR library_root_id = '' OR library_root_id IS NULL)", rootID)
 	}
 	rows, err := query.
-		Select("path", "library_root_id", "relative_path", "title", "original_name", "episode_title", "size_bytes", "duration_sec", "width", "height", "video_codec", "audio_codec", "container", "strm_url", "file_id", "poster_url", "backdrop_url", "overview", "year", "release_date", "rating", "tm_db_id", "bangumi_id", "douban_id", "thetvdb_id", "season_num", "episode_num", "episode_fraction", "genres", "countries", "languages", "nsfw", "scrape_status").
+		Select("path", "library_root_id", "relative_path", "title", "original_name", "episode_title", "size_bytes", "duration_sec", "width", "height", "video_codec", "audio_codec", "container", "strm_url", "file_id", "poster_url", "backdrop_url", "overview", "year", "release_date", "rating", "tm_db_id", "bangumi_id", "douban_id", "thetvdb_id", "season_num", "episode_num", "episode_fraction", "genres", "countries", "languages", "nsfw", "scrape_status", "availability_state", "missing_since").
 		Rows()
 	if err != nil {
 		return nil, err
@@ -80,6 +80,8 @@ func (s *ScannerService) existingLocalMediaSnapshotForRoot(ctx context.Context,
 			&row.Languages,
 			&row.NSFW,
 			&row.ScrapeStatus,
+			&row.AvailabilityState,
+			&row.MissingSince,
 		); err != nil {
 			return nil, err
 		}

internal/service/scanner_incremental_test.go

@@ -548,7 +548,7 @@ func TestScanLibraryMapsPersistedHostLibraryPath(t *testing.T) {
 	}
 }
 
-func TestRemovePathDeletesVanishedMedia(t *testing.T) {
+func TestRemovePathRetainsVanishedMedia(t *testing.T) {
 	sc, repos := newScannerTestEnv(t)
 	cache := NewRuntimeCacheService(&config.Config{}, zap.NewNop())
 	sc.SetRuntimeCache(cache)
@@ -589,8 +589,15 @@ func TestRemovePathDeletesVanishedMedia(t *testing.T) {
 	if removed != 1 {
 		t.Fatalf("removed = %d, want 1", removed)
 	}
-	if countMedia(t, repos) != 0 {
-		t.Fatal("expected 0 media after removal")
+	if countMedia(t, repos) != 1 {
+		t.Fatal("missing media metadata must be retained")
+	}
+	var missing model.Media
+	if err := repos.DB.Where("path = ?", file).First(&missing).Error; err != nil {
+		t.Fatal(err)
+	}
+	if missing.AvailabilityState != "missing" || missing.MissingSince == nil {
+		t.Fatalf("missing state not recorded: %#v", missing)
 	}
 	if cache.GetJSON(t.Context(), "media:list:test", &cached) {
 		t.Fatal("vanished media removal should invalidate media cache")

internal/service/scanner_library_roots_test.go

@@ -67,8 +67,16 @@ func TestScanLibraryScansMultipleRootsAndPrunesPerRoot(t *testing.T) {
 	if err := db.Find(&rows).Error; err != nil {
 		t.Fatal(err)
 	}
-	if len(rows) != 1 || rows[0].Path != fileB {
-		t.Fatalf("remaining rows = %#v, want offline root media preserved", rows)
+	if len(rows) != 2 {
+		t.Fatalf("remaining rows = %#v, want both media records preserved", rows)
+	}
+	for _, row := range rows {
+		if row.Path == fileA && row.AvailabilityState != "missing" {
+			t.Fatalf("vanished file was not marked missing: %#v", row)
+		}
+		if row.Path == fileB && row.AvailabilityState != "available" {
+			t.Fatalf("offline root status was changed: %#v", row)
+		}
 	}
 }
 

internal/service/scanner_local_ingest.go

@@ -122,7 +122,7 @@ func (s *ScannerService) localMediaScanState(in localMediaScanStateInput) (bool,
 	}
 	existing, exists := in.existingMedia[in.cleanPath]
 	isNewMedia := !exists
-	if exists && in.ext != ".strm" && existing.SizeBytes == in.size && !localMetadataNeedsRefresh(existing, in.localMeta) && !localDerivedMetadataNeedsRefresh(existing, in.incoming) {
+	if exists && existing.AvailabilityState != "missing" && existing.MissingSince == nil && in.ext != ".strm" && existing.SizeBytes == in.size && !localMetadataNeedsRefresh(existing, in.localMeta) && !localDerivedMetadataNeedsRefresh(existing, in.incoming) {
 		// Unchanged rows are skipped, but a row that never received ffprobe data
 		// still needs a backfill probe so installing ffmpeg later repairs the library.
 		s.queueProbeBackfillIfNeeded(in.path, in.ext, existing)

internal/service/scanner_local_metadata_test.go

@@ -372,7 +372,14 @@ func TestScanLibraryPrunesMissingMedia(t *testing.T) {
 	if err := db.Model(&model.Media{}).Where("library_id = ?", lib.ID).Count(&count).Error; err != nil {
 		t.Fatal(err)
 	}
-	if count != 1 {
-		t.Fatalf("media count = %d, want 1", count)
+	if count != 2 {
+		t.Fatalf("media count = %d, want current and missing records preserved", count)
+	}
+	var missing model.Media
+	if err := db.First(&missing, "id = ?", stale.ID).Error; err != nil {
+		t.Fatal(err)
+	}
+	if missing.AvailabilityState != "missing" {
+		t.Fatalf("stale media state = %q, want missing", missing.AvailabilityState)
 	}
 }

internal/service/scanner_missing_test.go

@@ -0,0 +1,55 @@
+package service
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/truewhile/MeBox/internal/model"
+)
+
+func TestScanRestoresUnchangedMissingFileAndMetadata(t *testing.T) {
+	scanner, repos := newScannerTestEnv(t)
+	root := t.TempDir()
+	library := model.Library{Name: "Movies", Path: root, Type: "movie", Enabled: true}
+	if err := repos.Library.Create(t.Context(), &library); err != nil {
+		t.Fatal(err)
+	}
+	path := filepath.Join(root, "Example (2024).mkv")
+	writeTestFile(t, path, "unchanged content")
+	if _, err := scanner.ScanLibrary(t.Context(), library.ID); err != nil {
+		t.Fatal(err)
+	}
+	var original model.Media
+	if err := repos.DB.Where("path = ?", path).First(&original).Error; err != nil {
+		t.Fatal(err)
+	}
+	if err := repos.DB.Model(&original).Updates(map[string]any{
+		"title": "Manually matched title", "scrape_status": "matched", "tm_db_id": 42,
+	}).Error; err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Remove(path); err != nil {
+		t.Fatal(err)
+	}
+	if changed, err := scanner.RemovePath(t.Context(), path); err != nil || changed != 1 {
+		t.Fatalf("mark missing: changed=%d err=%v", changed, err)
+	}
+	if changed, err := scanner.RemovePath(t.Context(), path); err != nil || changed != 0 {
+		t.Fatalf("repeated missing event: changed=%d err=%v", changed, err)
+	}
+	writeTestFile(t, path, "unchanged content")
+	if _, err := scanner.ScanLibrary(t.Context(), library.ID); err != nil {
+		t.Fatal(err)
+	}
+	var restored model.Media
+	if err := repos.DB.Where("path = ?", path).First(&restored).Error; err != nil {
+		t.Fatal(err)
+	}
+	if restored.ID != original.ID || restored.TMDbID != 42 || restored.Title != "Manually matched title" {
+		t.Fatalf("restored file lost identity or metadata: %#v", restored)
+	}
+	if restored.AvailabilityState != "available" || restored.MissingSince != nil || restored.LastSeenAt == nil {
+		t.Fatalf("unchanged restored file stayed missing: %#v", restored)
+	}
+}

internal/service/scanner_prune.go

@@ -2,6 +2,7 @@ package service
 
 import (
 	"context"
+	"errors"
 	"os"
 	"path/filepath"
 	"strings"
@@ -12,11 +13,15 @@ import (
 	"github.com/truewhile/MeBox/internal/model"
 )
 
-// RemovePath 移除磁盘上已不存在的媒体记录。普通的删除仍做物理删除；
-// 可确认是 STRM 扩展名改名的路径则先保留软删除墓碑，供后续 ingest 继承元数据。
+// RemovePath 将确认不存在的媒体标记为失联；只有可确认的 STRM 扩展名改名
+// 才保留软删除墓碑，供后续 ingest 继承元数据。
 func (s *ScannerService) RemovePath(ctx context.Context, path string) (int64, error) {
 	if _, err := os.Stat(path); err == nil {
 		return 0, nil // still exists; nothing to remove
+	} else if !errors.Is(err, os.ErrNotExist) {
+		// Permission, I/O, and mount errors are not evidence that a file was
+		// removed. Preserve records until the path can be inspected reliably.
+		return 0, nil
 	}
 	// 目录整体消失（删除/改名离开）：连同其子树下的媒体行一并移除。
 	// 此前只删 path 精确匹配的行——目录本身通常没有 media 行，导致目录
@@ -33,7 +38,7 @@ func (s *ScannerService) RemovePath(ctx context.Context, path string) (int64, er
 		return 0, err
 	}
 	softIDs := make([]string, 0, len(rows))
-	hardIDs := make([]string, 0, len(rows))
+	missingIDs := make([]string, 0, len(rows))
 	for _, row := range rows {
 		// LIKE 里的 % _ 是通配符（候选集只会偏大），用 Go 前缀精确过滤，
 		// 避免对含 % / _ 的路径误删。
@@ -43,12 +48,12 @@ func (s *ScannerService) RemovePath(ctx context.Context, path string) (int64, er
 		// A vanished STRM with a live sibling (foo.strm <-> foo.mkv.strm)
 		// is a rename. Keep a soft-deleted tombstone so the later ingest can
 		// adopt its ID and scraped metadata even if fsnotify delivers the
-		// remove event before the create event. A true deletion stays hard.
+		// remove event before the create event.
 		if row.Path == path && liveSTRMPathAlias(path) {
 			softIDs = append(softIDs, row.ID)
 			continue
 		}
-		hardIDs = append(hardIDs, row.ID)
+		missingIDs = append(missingIDs, row.ID)
 	}
 	var removed int64
 	if len(softIDs) > 0 {
@@ -60,14 +65,12 @@ func (s *ScannerService) RemovePath(ctx context.Context, path string) (int64, er
 		}
 		removed += res.RowsAffected
 	}
-	if len(hardIDs) > 0 {
-		res := s.repo.DB.WithContext(ctx).Unscoped().
-			Where("id IN ?", hardIDs).
-			Delete(&model.Media{})
-		if res.Error != nil {
-			return removed, res.Error
+	if len(missingIDs) > 0 {
+		count, err := s.markMediaMissingByIDs(ctx, missingIDs)
+		if err != nil {
+			return removed, err
 		}
-		removed += res.RowsAffected
+		removed += count
 	}
 	if removed > 0 {
 		s.invalidateMediaCache(ctx)
@@ -82,7 +85,7 @@ const strmRenameTombstoneRetention = 7 * 24 * time.Hour
 
 // purgeExpiredSTRMTombstones keeps the soft-delete grace period bounded.
 // It is deliberately restricted to deleted media rows under a STRM alias
-// workflow; normal deletions are still hard-deleted immediately.
+// workflow; ordinary missing files retain their metadata for recovery.
 func (s *ScannerService) purgeExpiredSTRMTombstones(ctx context.Context) {
 	cutoff := time.Now().Add(-strmRenameTombstoneRetention)
 	if err := s.repo.DB.WithContext(ctx).Unscoped().
@@ -121,7 +124,7 @@ func (s *ScannerService) pruneMissingMedia(ctx context.Context, libraryID string
 		}
 		stale = append(stale, row.ID)
 	}
-	return s.deleteMediaByIDs(ctx, stale, true)
+	return s.markMediaMissingByIDs(ctx, stale)
 }
 
 func (s *ScannerService) pruneMissingMediaForRoot(ctx context.Context, libraryID, rootID, rootPath string, seen map[string]struct{}) (int64, error) {
@@ -158,7 +161,33 @@ func (s *ScannerService) pruneMissingMediaForRoot(ctx context.Context, libraryID
 		}
 		stale = append(stale, row.ID)
 	}
-	return s.deleteMediaByIDs(ctx, stale, true)
+	return s.markMediaMissingByIDs(ctx, stale)
+}
+
+func (s *ScannerService) markMediaMissingByIDs(ctx context.Context, ids []string) (int64, error) {
+	if len(ids) == 0 {
+		return 0, nil
+	}
+	const batch = 500
+	var changed int64
+	now := time.Now()
+	for i := 0; i < len(ids); i += batch {
+		end := i + batch
+		if end > len(ids) {
+			end = len(ids)
+		}
+		result := s.repo.DB.WithContext(ctx).Model(&model.Media{}).
+			Where("id IN ? AND (availability_state IS NULL OR availability_state <> ?)", ids[i:end], "missing").
+			Updates(map[string]any{"availability_state": "missing", "missing_since": now})
+		if result.Error != nil {
+			return changed, result.Error
+		}
+		changed += result.RowsAffected
+	}
+	if changed > 0 {
+		s.invalidateMediaCache(ctx)
+	}
+	return changed, nil
 }
 
 func pathBelongsToRoot(pathValue, rootPath string) bool {

internal/service/scanner_scan.go

@@ -202,7 +202,7 @@ func (s *ScannerService) scanLocalLibraryFiles(ctx context.Context, lib *model.L
 func existingLocalMediaFileIDs(existingMedia map[string]existingLocalMedia) map[string]string {
 	seenInodes := make(map[string]string)
 	for path, existing := range existingMedia {
-		if existing.FileID != "" {
+		if existing.FileID != "" && existing.AvailabilityState != "missing" {
 			seenInodes[existing.FileID] = path
 		}
 	}

internal/service/scanner_strm_rename_test.go

@@ -175,7 +175,7 @@ func TestIngestPathAdoptsSoftDeletedSTRMRenameTombstone(t *testing.T) {
 	}
 }
 
-func TestRemovePathStillHardDeletesTrueDeletionWithoutAlias(t *testing.T) {
+func TestRemovePathRetainsTrueDeletionWithoutAlias(t *testing.T) {
 	sc, repos := newScannerTestEnv(t)
 	root := t.TempDir()
 	lib := model.Library{Name: "Anime", Path: root, Type: "anime", Enabled: true}
@@ -197,8 +197,15 @@ func TestRemovePathStillHardDeletesTrueDeletionWithoutAlias(t *testing.T) {
 	if err := repos.DB.Unscoped().Model(&model.Media{}).Where("path = ?", path).Count(&count).Error; err != nil {
 		t.Fatal(err)
 	}
-	if count != 0 {
-		t.Fatalf("true deletion left %d tombstone row(s)", count)
+	if count != 1 {
+		t.Fatalf("missing media count = %d, want metadata retained", count)
+	}
+	var media model.Media
+	if err := repos.DB.Where("path = ?", path).First(&media).Error; err != nil {
+		t.Fatal(err)
+	}
+	if media.AvailabilityState != "missing" || media.MissingSince == nil {
+		t.Fatalf("true deletion did not record missing state: %#v", media)
 	}
 }
 

internal/service/scheduler.go

@@ -50,6 +50,7 @@ type SchedulerService struct {
 	readerFilesTTLHours int
 
 	segments *MediaSegmentService
+	backup   *BackupService
 
 	mu     sync.Mutex
 	stopCh chan struct{}
@@ -65,6 +66,10 @@ func (s *SchedulerService) SetTaskTracker(tasks *TaskTrackerService) {
 	s.tasks = tasks
 }
 
+func (s *SchedulerService) SetBackupService(backup *BackupService) {
+	s.backup = backup
+}
+
 func (s *SchedulerService) SetOrganizePipeline(pipeline *OrganizePipelineService) {
 	s.organizePipeline = pipeline
 }
@@ -196,6 +201,13 @@ func (s *SchedulerService) Start(ctx context.Context) {
 			run:      s.jobTelegramExpiryWarning,
 		})
 	}
+	if s.backup != nil {
+		s.jobs = append(s.jobs, &scheduledJob{
+			name:     "database_backup",
+			interval: 5 * time.Minute,
+			run:      s.jobDatabaseBackup,
+		})
+	}
 	for _, j := range s.jobs {
 		initialDelay := 15 * time.Second
 		if j.name == "library_scan" || j.name == "organize_source" || j.name == "segment_prewarm" {

internal/service/scheduler_local_jobs.go

@@ -11,6 +11,53 @@ import (
 	"go.uber.org/zap"
 )
 
+const lastAutomaticBackupDateKey = "backup.last_automatic_date"
+
+func (s *SchedulerService) jobDatabaseBackup(ctx context.Context) error {
+	if s == nil || s.backup == nil || s.repo == nil || s.repo.Setting == nil {
+		return nil
+	}
+	enabled, _ := s.repo.Setting.Get(ctx, "backup.auto_enabled")
+	if !parseBoolSetting(enabled, false) {
+		return nil
+	}
+	clock, _ := s.repo.Setting.Get(ctx, "backup.auto_time")
+	if clock == "" {
+		clock = "03:00"
+	}
+	parsed, err := time.Parse("15:04", clock)
+	if err != nil {
+		return nil
+	}
+	now := s.currentTime().In(time.Local)
+	dueAt := time.Date(now.Year(), now.Month(), now.Day(), parsed.Hour(), parsed.Minute(), 0, 0, now.Location())
+	if now.Before(dueAt) {
+		return nil
+	}
+	date := now.Format("2006-01-02")
+	last, _ := s.repo.Setting.Get(ctx, lastAutomaticBackupDateKey)
+	if last == date {
+		return nil
+	}
+	if _, err := s.backup.CreateAutomatic(ctx); err != nil {
+		return err
+	}
+	// Record the successful backup before pruning. If retention cleanup fails,
+	// the next scheduler tick must not create another copy for the same day.
+	if err := s.repo.Setting.Set(ctx, lastAutomaticBackupDateKey, date); err != nil {
+		return err
+	}
+	retentionValue, _ := s.repo.Setting.Get(ctx, "backup.retention")
+	retention, err := strconv.Atoi(strings.TrimSpace(retentionValue))
+	if err != nil || retention < 1 {
+		retention = 7
+	}
+	if err := s.backup.Prune(retention); err != nil {
+		return err
+	}
+	return nil
+}
+
 // jobScanLibraries re-walks every enabled library.
 //
 // 默认关闭：文件变更由 WatcherService 增量入库，无需周期性全量重扫。

internal/service/service_builder.go

@@ -63,6 +63,9 @@ func (b *serviceContainerBuilder) startRealtimeServices() {
 	b.c.WSHub = NewHub(b.log)
 	helper.Go(b.log, "ws.hub", b.c.WSHub.Run)
 	b.c.Tasks = NewTaskTrackerService(b.log, b.c.WSHub)
+	if b.repos != nil {
+		b.c.Tasks.SetPersistence(b.repos.DB)
+	}
 	b.c.SystemUpdate = NewSystemUpdateService(b.cfg, b.log, b.repos, b.c.Tasks, b.version)
 
 	b.c.SSEHub = NewSSEHub(b.log)
@@ -206,6 +209,7 @@ func (b *serviceContainerBuilder) initAccessAndStorageServices() {
 		b.c.Organizer, b.c.WSHub, b.cfg.Cache.CacheDir,
 	)
 	b.c.Scheduler.SetTaskTracker(b.c.Tasks)
+	b.c.Scheduler.SetBackupService(b.c.Backup)
 	b.c.Scheduler.SetOrganizePipeline(b.c.OrganizePipeline)
 	b.c.Scheduler.SetSegments(b.c.Segments)
 	b.c.Scheduler.SetImageCachePolicyProvider(func() ImageCachePolicy {

internal/service/stream_direct_redirect_test.go

@@ -3,11 +3,13 @@ package service
 import (
 	"context"
 	"errors"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
 	"strings"
 	"testing"
+	"time"
 
 	"go.uber.org/zap"
 
@@ -15,6 +17,7 @@ import (
 	"github.com/truewhile/MeBox/internal/model"
 	"github.com/truewhile/MeBox/internal/repository"
 	"github.com/truewhile/MeBox/internal/service/cloud"
+	"github.com/truewhile/MeBox/internal/service/cloud115"
 )
 
 // directRedirectTestRepo 建一个带网盘账号表的库：normalizeCloudPlayTarget 需要
@@ -145,6 +148,53 @@ func TestServeFileFallsBackWhenDirectResolveUnavailable(t *testing.T) {
 	}
 }
 
+// `?refresh=1`：客户端手上的直链已被 CDN 403，服务端必须丢掉缓存重新换链，
+// 不能把同一条死链再发一次；不带该参数时缓存照旧命中，保住快路径。
+func TestServeFileRefreshDropsCachedDirectLink(t *testing.T) {
+	repos := directRedirectTestRepo(t)
+	seedCloudSTRMMedia(t, repos, "cloud-refresh", "/api/strm/play/cloud115/video.mkv?acct=a1&pickcode=pc-refresh")
+	cached := fmt.Sprintf("https://cdn.example/stale.mkv?t=%d", time.Now().Add(30*time.Minute).Unix())
+	fresh := "https://cdn.example/fresh.mkv?t=2"
+	cloud115.SetDownloadURLCache("pc-refresh", cached, "RodelPlayer/2.0")
+	t.Cleanup(func() { cloud115.ClearDownloadURLCache("pc-refresh") })
+	oldMinAge := directLinkRefreshMinAge
+	directLinkRefreshMinAge = 0
+	defer func() { directLinkRefreshMinAge = oldMinAge }()
+
+	run := func(t *testing.T, query string) (cachedAtResolve, location string) {
+		t.Helper()
+		svc := NewStreamService(&config.Config{}, zap.NewNop(), repos, nil).
+			SetStrmPlayTargetResolver(func(_ context.Context, _ string, userAgent string) (*StrmPlayResult, error) {
+				cachedAtResolve = cloud115.GetDownloadURLCache("pc-refresh", userAgent)
+				return &StrmPlayResult{
+					RedirectURL: fresh,
+					Link:        &cloud.DirectLink{URL: fresh, Headers: map[string]string{"User-Agent": userAgent}},
+				}, nil
+			})
+		req := httptest.NewRequest(http.MethodGet, "http://nas.local:18080/api/stream/cloud-refresh?token=jwt123"+query, nil)
+		req.Header.Set("User-Agent", "RodelPlayer/2.0")
+		w := httptest.NewRecorder()
+		if err := svc.ServeFile(w, req, "cloud-refresh"); err != nil {
+			t.Fatalf("ServeFile: %v", err)
+		}
+		return cachedAtResolve, w.Header().Get("Location")
+	}
+
+	// 正常播放：缓存里的直链照旧命中，服务端不该白跑一次换链。
+	if got, loc := run(t, ""); got != cached {
+		t.Fatalf("cached link = %q, want the cached %q", got, cached)
+	} else if loc != fresh {
+		t.Fatalf("Location = %q, want the resolved direct link", loc)
+	}
+
+	// 客户端报告直链失效：换链前必须先清掉缓存。
+	if got, loc := run(t, "&refresh=1"); got != "" {
+		t.Fatalf("cached link must be dropped before resolving, got %q", got)
+	} else if loc != fresh {
+		t.Fatalf("Location = %q, want the freshly resolved direct link", loc)
+	}
+}
+
 // 没有注入解析器（测试/精简部署）时保持原有跳转，不受本次优化影响。
 func TestServeFileKeepsSTRMEndpointWithoutResolver(t *testing.T) {
 	repos := directRedirectTestRepo(t)

internal/service/stream_file.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/truewhile/MeBox/internal/model"
 	"github.com/truewhile/MeBox/internal/repository"
+	"github.com/truewhile/MeBox/internal/service/cloud115"
 )
 
 // ServeFile streams the file backing the given media ID using
@@ -22,6 +23,47 @@ func (s *StreamService) ServeFile(w http.ResponseWriter, r *http.Request, mediaI
 	return s.ServeFileWithCloudMode(w, r, mediaID, "")
 }
 
+// PickCodeFromPlayTarget 从 /api/strm/play/... 形式的播放目标里取出 pickcode。
+// 115 直链缓存按 pickcode 分键，客户端要求强制换链时用它定位缓存条目。
+func PickCodeFromPlayTarget(raw string) string {
+	u, err := url.Parse(strings.TrimSpace(raw))
+	if err != nil || u == nil {
+		return ""
+	}
+	return strings.TrimSpace(u.Query().Get("pickcode"))
+}
+
+// directLinkRefreshMinAge 是「强制换链」的最小间隔：缓存条目刚写入不久就
+// 收到换链请求时忽略它，避免客户端重试风暴把 115 换链接口打出突发。
+// 测试会临时改成 0，让「CDN 拒绝 → 立刻换链」的路径可验证。
+var directLinkRefreshMinAge = 30 * time.Second
+
+// wantsFreshLink 判断客户端是否要求跳过直链缓存重新换链（`?refresh=1`）。
+//
+// 115 直链只有 30 分钟有效期，客户端拿到过期直链被 CDN 403 后需要一条新链；
+// 正常路径下缓存会先于直链过期，这里是客户端上报失败时的兜底。
+func wantsFreshLink(r *http.Request) bool {
+	if r == nil {
+		return false
+	}
+	switch strings.ToLower(strings.TrimSpace(r.URL.Query().Get("refresh"))) {
+	case "1", "true", "yes":
+		return true
+	default:
+		return false
+	}
+}
+
+// InvalidateMediaLinkCache 清除媒体播放目标对应的云盘直链缓存，让下一次解析
+// 重新换链。非云盘/无 pickcode 的媒体是空操作。
+func InvalidateMediaLinkCache(m *model.Media) {
+	pickCode := PickCodeFromPlayTarget(MediaSTRMTarget(m))
+	if pickCode == "" {
+		return
+	}
+	cloud115.ClearDownloadURLCacheIfOlderThan(pickCode, directLinkRefreshMinAge)
+}
+
 // MediaSTRMTarget 返回媒体行固化的 STRM 播放目标。STRMURL 为空时回读本地
 // .strm 文件内容兜底（扫描时内容解析失败的行只剩 Container=strm + Path），
 // 仍拿不到返回空串。
@@ -57,6 +99,11 @@ func (s *StreamService) ServeFileWithCloudMode(w http.ResponseWriter, r *http.Re
 		// 能在服务端换到最终直链就直接 302 过去：客户端少跟随一次 302，等于
 		// 省掉一次「DNS+TCP+TLS+请求」的往返。解析结果同时写进 strm 层直链
 		// 缓存，后续 /api/strm/play 请求直接命中。
+		// `?refresh=1` 表示客户端手上的直链已经失效（被 CDN 403），要求丢掉
+		// 缓存重新换链。
+		if wantsFreshLink(r) {
+			InvalidateMediaLinkCache(m)
+		}
 		if direct, ok := s.resolveDirectPlayTargetURL(r, strmURL); ok {
 			setCloudRedirectNoStore(w)
 			http.Redirect(w, r, direct, http.StatusFound)

internal/service/stream_hls.go

@@ -17,7 +17,8 @@ import (
 // Optional query `start` (seconds) restarts ffmpeg from that source offset so
 // the web player can scrub the full timeline without waiting for a full
 // head-to-tail transcode.
-func (s *StreamService) ServeHLSPlaylist(w http.ResponseWriter, r *http.Request, mediaID string) error {
+func (s *StreamService) ServeHLSPlaylist(w http.ResponseWriter, r *http.Request, mediaID string, scopes ...HLSPlaybackScope) error {
+	jobKey := hlsPlaybackJobKey(mediaID, scopes)
 	// 「客户端直连解码」模式下宿主机不提供转码，HLS 一律拒绝，
 	// 迫使播放器走 direct play 本地解码。
 	if s.directPlayOnly(r.Context()) {
@@ -27,19 +28,23 @@ func (s *StreamService) ServeHLSPlaylist(w http.ResponseWriter, r *http.Request,
 	seekGen := parseHLSSeekGen(r)
 	subtitleStream := parseHLSSubtitleStream(r)
 	quality := parseHLSQuality(r)
-	if _, err := s.transcoder.EnsureJobFromSubtitleQuality(r.Context(), mediaID, startSec, seekGen, subtitleStream, quality); err != nil {
+	if _, err := s.transcoder.EnsureJobFromSubtitleQuality(r.Context(), mediaID, startSec, seekGen, subtitleStream, quality, scopes...); err != nil {
 		return err
 	}
-	s.transcoder.TouchJob(mediaID)
+	s.transcoder.TouchJob(jobKey)
 	readyTimeout := 45 * time.Second
 	if startSec > 0.05 {
 		// Mid-file HTTP seeks (esp. WMV) need longer before the first segment appears.
 		readyTimeout = 120 * time.Second
 	}
-	if !s.transcoder.WaitReady(r.Context(), mediaID, readyTimeout) {
+	if !s.transcoder.WaitReady(r.Context(), jobKey, readyTimeout) {
 		return errors.New("hls playlist not ready")
 	}
-	playlist := s.transcoder.PlaylistPath(mediaID)
+	outputDir, err := s.transcoder.hlsOutputDir(jobKey, seekGen)
+	if err != nil {
+		return err
+	}
+	playlist := filepath.Join(outputDir, "index.m3u8")
 	f, err := os.Open(playlist) // #nosec G304 -- playlist path is generated under the transcoder cache directory for this media ID.
 	if err != nil {
 		return err
@@ -49,12 +54,18 @@ func (s *StreamService) ServeHLSPlaylist(w http.ResponseWriter, r *http.Request,
 	w.Header().Set("Content-Type", "application/vnd.apple.mpegurl")
 	w.Header().Set("Cache-Control", "no-cache")
 	w.Header().Set("Content-Disposition", "inline")
-	if r.URL.RawQuery != "" {
+	rawQuery := r.URL.RawQuery
+	if len(scopes) > 0 && scopes[0].SessionID != "" {
+		query := r.URL.Query()
+		query.Set("session_id", scopes[0].SessionID)
+		rawQuery = query.Encode()
+	}
+	if rawQuery != "" {
 		data, err := io.ReadAll(f)
 		if err != nil {
 			return err
 		}
-		playlist := appendQueryToHLSSegments(string(data), r.URL.RawQuery)
+		playlist := appendQueryToHLSSegments(string(data), rawQuery)
 		_, err = io.WriteString(w, playlist)
 		return err
 	}
@@ -171,19 +182,26 @@ func filterHLSSegmentQuery(rawQuery string) string {
 }
 
 // ServeHLSSegment writes a single .ts segment from the on-disk cache.
-func (s *StreamService) ServeHLSSegment(w http.ResponseWriter, r *http.Request, mediaID, segment string) error {
-	s.transcoder.TouchJob(mediaID)
+func (s *StreamService) ServeHLSSegment(w http.ResponseWriter, r *http.Request, mediaID, segment string, scopes ...HLSPlaybackScope) error {
+	jobKey := hlsPlaybackJobKey(mediaID, scopes)
+	outputDir, err := s.transcoder.hlsOutputDir(jobKey, parseHLSSeekGen(r))
+	if err != nil {
+		if len(scopes) > 0 || parseHLSSeekGen(r) > 0 {
+			return err
+		}
+		outputDir = s.transcoder.HLSDir(jobKey) // Legacy internal static-file callers.
+	}
 	// Only allow segments that look like seg_NNNNN.ts so we cannot be tricked
 	// into reading arbitrary files via path traversal.
 	if !strings.HasPrefix(segment, "seg_") || !strings.HasSuffix(segment, ".ts") {
 		return errors.New("bad segment")
 	}
-	full := filepath.Join(s.transcoder.HLSDir(mediaID), segment)
+	full := filepath.Join(outputDir, segment)
 	abs, err := filepath.Abs(full)
 	if err != nil {
 		return err
 	}
-	dir, _ := filepath.Abs(s.transcoder.HLSDir(mediaID))
+	dir, _ := filepath.Abs(outputDir)
 	if !pathWithin(abs, dir) {
 		return errors.New("path escape")
 	}

internal/service/strm_play.go

@@ -16,6 +16,7 @@ import (
 
 	"github.com/truewhile/MeBox/internal/model"
 	"github.com/truewhile/MeBox/internal/service/cloud"
+	"github.com/truewhile/MeBox/internal/service/cloud115"
 )
 
 // ErrStrmPlayNotFound 表示 strm 播放目标不存在（handler 返回 404）。
@@ -250,21 +251,87 @@ func (s *StrmService) ProxyMediaDirect(ctx context.Context, w http.ResponseWrite
 	if err != nil {
 		return err
 	}
-	switch {
-	case result.Link != nil && result.Link.URL != "":
-		return s.ProxyDirect(ctx, w, r, result.Link)
-	case result.RedirectURL != "":
-		return s.ProxyDirect(ctx, w, r, &cloud.DirectLink{URL: result.RedirectURL})
-	default:
+	link := directLinkOfPlayResult(result)
+	if link == nil {
 		// 本地文件（LocalPath）由静态文件处理器提供，本身就是同源。
 		return ErrStrmProxyNotApplicable
 	}
+	resp, method, err := s.openDirectUpstream(ctx, r, link)
+	if err != nil {
+		return err
+	}
+	// 直链被 CDN 拒绝：115 直链带 30 分钟过期时间戳，缓存命中也可能拿到已经
+	// 失效的地址。这里清掉缓存重新换链再试一次，避免客户端只看到 403。
+	if directLinkRejected(resp.StatusCode) {
+		_ = resp.Body.Close()
+		if fresh := s.refreshDirectLink(ctx, raw); fresh != nil {
+			if retry, retryMethod, retryErr := s.openDirectUpstream(ctx, r, fresh); retryErr == nil {
+				resp, method = retry, retryMethod
+			}
+		}
+	}
+	defer resp.Body.Close()
+	return writeDirectUpstream(w, resp, method)
+}
+
+// directLinkOfPlayResult 取出可反向代理的直链；本地文件返回 nil。
+func directLinkOfPlayResult(result *StrmPlayResult) *cloud.DirectLink {
+	if result == nil {
+		return nil
+	}
+	switch {
+	case result.Link != nil && result.Link.URL != "":
+		return result.Link
+	case result.RedirectURL != "":
+		return &cloud.DirectLink{URL: result.RedirectURL}
+	default:
+		return nil
+	}
+}
+
+// directLinkRejected 判断上游状态码是否属于「直链本身失效」（而不是文件/权限
+// 之类与链接无关的问题）。
+func directLinkRejected(status int) bool {
+	switch status {
+	case http.StatusForbidden, http.StatusNotFound, http.StatusGone:
+		return true
+	default:
+		return false
+	}
+}
+
+// refreshDirectLink 丢弃当前直链缓存并重新换链，返回新的直链；无法换链时返回
+// nil，调用方继续用原来那条。
+func (s *StrmService) refreshDirectLink(ctx context.Context, raw string) *cloud.DirectLink {
+	pickCode := PickCodeFromPlayTarget(raw)
+	if pickCode == "" {
+		return nil
+	}
+	if !cloud115.ClearDownloadURLCacheIfOlderThan(pickCode, directLinkRefreshMinAge) {
+		// 缓存刚写入不久：说明失败与链接过期无关，重换一次也会拿到同一条。
+		return nil
+	}
+	fresh, err := s.ResolvePlayTarget(ctx, raw)
+	if err != nil {
+		return nil
+	}
+	return directLinkOfPlayResult(fresh)
 }
 
 // ProxyDirect 反向代理渲染直链内容（保留 Range 请求头以支持拖动播放）。
 func (s *StrmService) ProxyDirect(ctx context.Context, w http.ResponseWriter, r *http.Request, link *cloud.DirectLink) error {
+	resp, method, err := s.openDirectUpstream(ctx, r, link)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	return writeDirectUpstream(w, resp, method)
+}
+
+// openDirectUpstream 向网盘直链发起一次请求，保留 Range 与 UA 语义。
+func (s *StrmService) openDirectUpstream(ctx context.Context, r *http.Request, link *cloud.DirectLink) (*http.Response, string, error) {
 	if link == nil || link.URL == "" {
-		return errors.New("空直链")
+		return nil, "", errors.New("空直链")
 	}
 	method := http.MethodGet
 	if r != nil && r.Method == http.MethodHead {
@@ -272,7 +339,7 @@ func (s *StrmService) ProxyDirect(ctx context.Context, w http.ResponseWriter, r
 	}
 	req, err := http.NewRequestWithContext(ctx, method, link.URL, nil)
 	if err != nil {
-		return err
+		return nil, "", err
 	}
 	for k, v := range link.Headers {
 		req.Header.Set(k, v)
@@ -288,9 +355,13 @@ func (s *StrmService) ProxyDirect(ctx context.Context, w http.ResponseWriter, r
 	}
 	resp, err := s.streamHTTP.Do(req)
 	if err != nil {
-		return err
+		return nil, "", err
 	}
-	defer resp.Body.Close()
+	return resp, method, nil
+}
+
+// writeDirectUpstream 把上游响应原样写给客户端。
+func writeDirectUpstream(w http.ResponseWriter, resp *http.Response, method string) error {
 	for _, header := range []string{"Content-Type", "Content-Length", "Content-Range", "Accept-Ranges", "ETag", "Last-Modified"} {
 		if value := resp.Header.Get(header); value != "" {
 			w.Header().Set(header, value)
@@ -310,7 +381,7 @@ func (s *StrmService) ProxyDirect(ctx context.Context, w http.ResponseWriter, r
 	if flusher, ok := w.(http.Flusher); ok {
 		writer = &flushWriter{writer: w, flusher: flusher}
 	}
-	_, err = io.Copy(writer, resp.Body)
+	_, err := io.Copy(writer, resp.Body)
 	return err
 }
 

internal/service/strm_proxy_test.go

@@ -3,12 +3,16 @@ package service
 import (
 	"context"
 	"errors"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"path/filepath"
+	"sync"
 	"testing"
+	"time"
 
 	"github.com/truewhile/MeBox/internal/model"
+	"github.com/truewhile/MeBox/internal/service/cloud115"
 )
 
 // 同源转发必须原样保留 Range 语义：把 206 改写成 200 会让浏览器误判响应长度，
@@ -55,6 +59,134 @@ func TestProxyMediaDirectForwardsRangeAndStatus(t *testing.T) {
 	}
 }
 
+// 115 直链只有 30 分钟寿命，缓存命中也可能拿到已经失效的地址。同源转发遇到
+// CDN 403 时必须丢掉缓存重新换链再试一次，而不是把 403 直接透给客户端。
+func TestProxyMediaDirectRetriesWithFreshLinkWhenCDNRejects(t *testing.T) {
+	svc := testStrmService(t)
+	acct := &model.StrmAccount{Name: "fake115", Provider: model.StrmProvider115, Config: "{}", Enabled: true}
+	if err := svc.repo.StrmAccount.Create(context.Background(), acct); err != nil {
+		t.Fatal(err)
+	}
+
+	cdn := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/fresh.mkv" {
+			w.WriteHeader(http.StatusForbidden)
+			return
+		}
+		w.Header().Set("Content-Type", "video/x-matroska")
+		w.WriteHeader(http.StatusPartialContent)
+		_, _ = w.Write([]byte("fresh-bytes"))
+	}))
+	defer cdn.Close()
+
+	// 第一次换链给出「已过期」的旧地址，重新换链才给新地址。
+	var mu sync.Mutex
+	var calls int
+	expiry := time.Now().Add(30 * time.Minute).Unix()
+	api := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		mu.Lock()
+		calls++
+		attempt := calls
+		mu.Unlock()
+		link := cdn.URL + "/old.mkv"
+		if attempt > 1 {
+			link = cdn.URL + "/fresh.mkv"
+		}
+		_, _ = fmt.Fprintf(w, `{"state":true,"data":{"1":{"pick_code":"pc-retry","url":{"url":%q}}}}`,
+			fmt.Sprintf("%s?t=%d&u=1&k=abc", link, expiry))
+	}))
+	defer api.Close()
+	oldPro := cloud115.ProAPIBase
+	cloud115.ProAPIBase = api.URL
+	defer func() { cloud115.ProAPIBase = oldPro }()
+	defer cloud115.ClearDownloadURLCache("pc-retry")
+	oldMinAge := directLinkRefreshMinAge
+	directLinkRefreshMinAge = 0
+	defer func() { directLinkRefreshMinAge = oldMinAge }()
+
+	media := &model.Media{
+		STRMURL: "/api/strm/play/cloud115/video.mkv?acct=" + acct.ID + "&pickcode=pc-retry",
+	}
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/api/stream/media-1?proxy=1", nil)
+	req.Header.Set("User-Agent", "MeBoxTest/1.0")
+
+	if err := svc.ProxyMediaDirect(context.Background(), rec, req, media); err != nil {
+		t.Fatalf("ProxyMediaDirect: %v", err)
+	}
+	if rec.Code != http.StatusPartialContent {
+		t.Fatalf("status = %d, want 206 (body=%s)", rec.Code, rec.Body.String())
+	}
+	if rec.Body.String() != "fresh-bytes" {
+		t.Fatalf("body = %q, want the fresh link payload", rec.Body.String())
+	}
+	mu.Lock()
+	defer mu.Unlock()
+	if calls != 2 {
+		t.Fatalf("downurl calls = %d, want 2 (one retry after the CDN rejected the stale link)", calls)
+	}
+}
+
+// 换链后依然是同一条失效直链时，保持原有行为：原样透传 CDN 的状态码。
+func TestProxyMediaDirectPassesRejectedStatusWhenRefreshCannotHelp(t *testing.T) {
+	svc := testStrmService(t)
+	acct := &model.StrmAccount{Name: "fake115", Provider: model.StrmProvider115, Config: "{}", Enabled: true}
+	if err := svc.repo.StrmAccount.Create(context.Background(), acct); err != nil {
+		t.Fatal(err)
+	}
+
+	cdn := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusForbidden)
+	}))
+	defer cdn.Close()
+
+	expiry := time.Now().Add(30 * time.Minute).Unix()
+	api := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, _ = fmt.Fprintf(w, `{"state":true,"data":{"1":{"pick_code":"pc-dead","url":{"url":%q}}}}`,
+			fmt.Sprintf("%s/dead.mkv?t=%d&u=1&k=abc", cdn.URL, expiry))
+	}))
+	defer api.Close()
+	oldPro := cloud115.ProAPIBase
+	cloud115.ProAPIBase = api.URL
+	defer func() { cloud115.ProAPIBase = oldPro }()
+	defer cloud115.ClearDownloadURLCache("pc-dead")
+	oldMinAge := directLinkRefreshMinAge
+	directLinkRefreshMinAge = 0
+	defer func() { directLinkRefreshMinAge = oldMinAge }()
+
+	media := &model.Media{
+		STRMURL: "/api/strm/play/cloud115/video.mkv?acct=" + acct.ID + "&pickcode=pc-dead",
+	}
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/api/stream/media-1?proxy=1", nil)
+
+	if err := svc.ProxyMediaDirect(context.Background(), rec, req, media); err != nil {
+		t.Fatalf("ProxyMediaDirect: %v", err)
+	}
+	if rec.Code != http.StatusForbidden {
+		t.Fatalf("status = %d, want the upstream 403 passed through", rec.Code)
+	}
+}
+
+// 强制换链只认 /api/strm/play 形式播放目标里的 pickcode。
+func TestPickCodeFromPlayTarget(t *testing.T) {
+	cases := []struct {
+		raw  string
+		want string
+	}{
+		{"/api/strm/play/cloud115/video.mkv?acct=a1&pickcode=pc1", "pc1"},
+		{"https://nas.local/api/strm/play/cloud115/video.mkv?pickcode=pc2&acct=a1", "pc2"},
+		{"/api/strm/play/cloud115/video.mkv?acct=a1", ""},
+		{"https://cdn.example.test/Movie.mkv?sign=1", ""},
+		{"", ""},
+	}
+	for _, tc := range cases {
+		if got := PickCodeFromPlayTarget(tc.raw); got != tc.want {
+			t.Fatalf("PickCodeFromPlayTarget(%q) = %q, want %q", tc.raw, got, tc.want)
+		}
+	}
+}
+
 // 本地文件本身就是同源资源，不应该被代理（调用方按原静态文件逻辑处理）。
 func TestProxyMediaDirectSkipsLocalFile(t *testing.T) {
 	svc := testStrmService(t)

internal/service/subtitle.go

@@ -182,6 +182,77 @@ func (s *SubtitleService) discoverExternalUncached(ctx context.Context, mediaID
 	return discoverExternalSubtitleTracks(m), nil
 }
 
+// subtitleLanguageNames 把文件名后缀/容器里的语言标记折成可读名称。
+//
+// 外挂字幕只能从文件名拿到语言（`movie.chs.ass` → `chs`），直接展示给用户
+// 就是「chs」这种看不懂的值；内嵌轨没有 title 标签时同理。认不出来的标记
+// 原样保留，交给调用方（例如 Emby 的「字幕 (ASS)」兜底）处理。
+var subtitleLanguageNames = map[string]string{
+	"zh":  "中文",
+	"chi": "中文",
+	"zho": "中文",
+	"cn":  "中文",
+
+	"chs":     "简体中文",
+	"sc":      "简体中文",
+	"zh-cn":   "简体中文",
+	"zh-hans": "简体中文",
+	"zh-sg":   "简体中文",
+
+	"cht":     "繁体中文",
+	"tc":      "繁体中文",
+	"zh-tw":   "繁体中文",
+	"zh-hk":   "繁体中文",
+	"zh-mo":   "繁体中文",
+	"zh-hant": "繁体中文",
+
+	"jpn": "日本語",
+	"ja":  "日本語",
+	"jp":  "日本語",
+
+	"eng": "English",
+	"en":  "English",
+
+	"kor": "한국어",
+	"ko":  "한국어",
+
+	"yue": "粤语",
+}
+
+// subtitleLanguageName 返回语言标记的可读名称，认不出来时返回空串。
+func subtitleLanguageName(raw string) string {
+	tag := strings.ToLower(strings.TrimSpace(strings.ReplaceAll(raw, "_", "-")))
+	if tag == "" {
+		return ""
+	}
+	if name, ok := subtitleLanguageNames[tag]; ok {
+		return name
+	}
+	// `chs[bilibiliid_danmu]`、`chs.ass` 这类带附加信息的标记先取前缀。
+	head := tag
+	if i := strings.IndexAny(head, "[.@"); i > 0 {
+		head = strings.TrimSpace(head[:i])
+	}
+	return subtitleLanguageNames[head]
+}
+
+// subtitleDisplayLabel 把语言标记换成可读名称；认不出来时保留原值（含 und）。
+func subtitleDisplayLabel(raw string) string {
+	if name := subtitleLanguageName(raw); name != "" {
+		return name
+	}
+	return strings.TrimSpace(raw)
+}
+
+// isDanmakuSubtitle 报告字幕文件是否是弹幕转存（`xxx[BilibiliID_danmu].ass`）。
+// 这类轨道是飘过的弹幕而不是对白字幕，名称里要标出来，避免和对白字幕混淆。
+func isDanmakuSubtitle(name string) bool {
+	lower := strings.ToLower(name)
+	return strings.Contains(lower, "danmu") ||
+		strings.Contains(lower, "danmaku") ||
+		strings.Contains(name, "弹幕")
+}
+
 func discoverExternalSubtitleTracks(m *model.Media) []SubtitleTrack {
 	dir := filepath.Dir(m.Path)
 	bases := mediaSidecarBaseVariants(m.Path)
@@ -228,9 +299,13 @@ func discoverExternalSubtitleTracks(m *model.Media) []SubtitleTrack {
 				matchedBase = bases[0]
 			}
 			lang := detectLang(fullName, matchedBase)
+			label := subtitleDisplayLabel(lang)
+			if isDanmakuSubtitle(e.Name()) {
+				label += " · 弹幕"
+			}
 			tracks = append(tracks, SubtitleTrack{
 				Lang:     lang,
-				Label:    lang,
+				Label:    label,
 				Path:     filepath.Join(c, e.Name()),
 				Codec:    codec,
 				Source:   "external",
@@ -319,7 +394,11 @@ func subtitleTracksFromProbe(probe embeddedSubtitleProbe) []SubtitleTrack {
 		}
 		label := strings.TrimSpace(stream.Tags.Title)
 		if label == "" {
-			label = lang
+			// 没有 title 标签时用可读语言名（chi → 中文）代替裸语言码。
+			label = subtitleDisplayLabel(lang)
+		}
+		if label == "" {
+			label = "字幕"
 		}
 		if stream.Disposition.Forced != 0 {
 			label += "（强制）"

internal/service/subtitle_test.go

@@ -202,3 +202,103 @@ func TestSubtitleServeRawWritesSourceBytes(t *testing.T) {
 		t.Fatal("ServeRaw accepted a non-subtitle file")
 	}
 }
+
+func TestSubtitleLanguageNameMapsCommonTags(t *testing.T) {
+	cases := map[string]string{
+		"chs":                   "简体中文",
+		"CHS":                   "简体中文",
+		"zh-Hans":               "简体中文",
+		"cht":                   "繁体中文",
+		"chi":                   "中文",
+		"zh":                    "中文",
+		"jpn":                   "日本語",
+		"eng":                   "English",
+		"kor":                   "한국어",
+		"chs[bilibiliid_danmu]": "简体中文",
+		"und":                   "",
+		"":                      "",
+	}
+	for raw, want := range cases {
+		if got := subtitleLanguageName(raw); got != want {
+			t.Errorf("subtitleLanguageName(%q) = %q, want %q", raw, got, want)
+		}
+	}
+}
+
+func TestSubtitleDisplayLabelKeepsUnknownTags(t *testing.T) {
+	// 认不出来的标记原样返回：Emby 的 DisplayTitle 依赖 `und` 走「字幕 (ASS)」兜底。
+	if got := subtitleDisplayLabel("und"); got != "und" {
+		t.Fatalf("subtitleDisplayLabel(und) = %q, want und", got)
+	}
+	if got := subtitleDisplayLabel("weird"); got != "weird" {
+		t.Fatalf("subtitleDisplayLabel(weird) = %q, want weird", got)
+	}
+}
+
+func TestIsDanmakuSubtitle(t *testing.T) {
+	if !isDanmakuSubtitle("S01E01.chs[BilibiliID_danmu].ass") {
+		t.Fatal("danmaku sidecar was not detected")
+	}
+	if !isDanmakuSubtitle("弹幕.ass") {
+		t.Fatal("Chinese danmaku name was not detected")
+	}
+	if isDanmakuSubtitle("S01E01.chs.ass") {
+		t.Fatal("normal subtitle was misdetected as danmaku")
+	}
+}
+
+func TestDiscoverExternalSubtitleLabelsAreReadable(t *testing.T) {
+	dir := t.TempDir()
+	videoPath := filepath.Join(dir, "S01E01.mkv")
+	files := map[string]string{
+		"S01E01.chs.ass":                   "[Script Info]\n",
+		"S01E01.chs[BilibiliID_danmu].ass": "[Script Info]\n",
+	}
+	for name, body := range files {
+		if err := os.WriteFile(filepath.Join(dir, name), []byte(body), 0o600); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	m := &model.Media{Path: videoPath}
+	tracks := discoverExternalSubtitleTracks(m)
+	if len(tracks) != 2 {
+		t.Fatalf("len(tracks) = %d, want 2: %#v", len(tracks), tracks)
+	}
+	labels := map[string]string{}
+	for _, track := range tracks {
+		labels[filepath.Base(track.Path)] = track.Label
+	}
+	if got := labels["S01E01.chs.ass"]; got != "简体中文" {
+		t.Fatalf("chs.ass label = %q, want 简体中文", got)
+	}
+	if got := labels["S01E01.chs[BilibiliID_danmu].ass"]; got != "简体中文 · 弹幕" {
+		t.Fatalf("danmaku label = %q, want 简体中文 · 弹幕", got)
+	}
+}
+
+func TestEmbeddedSubtitleProbeUsesReadableLanguage(t *testing.T) {
+	var probe embeddedSubtitleProbe
+	raw := []byte(`{"streams":[
+		{"index":2,"codec_name":"hdmv_pgs_subtitle","tags":{"language":"chi"},"disposition":{"default":1}},
+		{"index":3,"codec_name":"subrip","tags":{"language":"jpn"}},
+		{"index":4,"codec_name":"subrip","tags":{"language":"chi","title":"简日双语"}}
+	]}`)
+	if err := json.Unmarshal(raw, &probe); err != nil {
+		t.Fatal(err)
+	}
+	tracks := subtitleTracksFromProbe(probe)
+	if len(tracks) != 3 {
+		t.Fatalf("len(tracks) = %d, want 3", len(tracks))
+	}
+	if got := tracks[0].Label; got != "中文（默认）（内嵌·图片）" {
+		t.Fatalf("bitmap label = %q", got)
+	}
+	if got := tracks[1].Label; got != "日本語（内嵌）" {
+		t.Fatalf("text label = %q", got)
+	}
+	// 容器自带 title 时优先用 title。
+	if got := tracks[2].Label; got != "简日双语（内嵌）" {
+		t.Fatalf("titled label = %q", got)
+	}
+}

internal/service/task_tracker.go

@@ -2,6 +2,7 @@ package service
 
 import (
 	"context"
+	"encoding/json"
 	"html"
 	"strings"
 	"sync"
@@ -9,12 +10,16 @@ import (
 
 	"github.com/google/uuid"
 	"go.uber.org/zap"
+	"gorm.io/gorm"
+
+	"github.com/truewhile/MeBox/internal/model"
 )
 
 const (
-	TaskStatusRunning   = "running"
-	TaskStatusCompleted = "completed"
-	TaskStatusFailed    = "failed"
+	TaskStatusRunning     = "running"
+	TaskStatusCompleted   = "completed"
+	TaskStatusFailed      = "failed"
+	TaskStatusInterrupted = "interrupted"
 
 	TaskKindOrganize = "organize"
 	TaskKindScan     = "scan"
@@ -70,6 +75,26 @@ type TaskTrackerService struct {
 	recent    []BackgroundTask
 	maxRecent int
 	now       func() time.Time
+	db        *gorm.DB
+}
+
+// SetPersistence enables durable task history and marks tasks left running by
+// a previous process as interrupted. Actual task execution is never resumed
+// automatically; this record is an operator-visible recovery point.
+func (t *TaskTrackerService) SetPersistence(db *gorm.DB) {
+	if t == nil || db == nil {
+		return
+	}
+	t.mu.Lock()
+	t.db = db
+	now := t.currentTime()
+	t.mu.Unlock()
+	err := db.Model(&model.BackgroundTaskRecord{}).
+		Where("status = ?", TaskStatusRunning).
+		Updates(map[string]any{"status": TaskStatusInterrupted, "error": "服务在任务完成前重启；请检查文件状态后重新执行", "updated_at": now, "finished_at": now}).Error
+	if err != nil && t.log != nil {
+		t.log.Warn("recover interrupted background tasks failed", zap.Error(err))
+	}
 }
 
 type TaskHandle struct {
@@ -105,9 +130,11 @@ func (t *TaskTrackerService) Start(kind, name string, update TaskUpdate) *TaskHa
 		StartedAt:  now,
 		UpdatedAt:  now,
 	}
+	applyTaskUpdate(task, update)
 	t.mu.Lock()
 	t.active[task.ID] = task
 	snapshot := cloneBackgroundTask(*task)
+	t.persist(snapshot)
 	t.mu.Unlock()
 	t.publish(snapshot)
 	return &TaskHandle{tracker: t, id: task.ID}
@@ -132,18 +159,47 @@ func (t *TaskTrackerService) Snapshot() TaskSnapshot {
 		return TaskSnapshot{}
 	}
 	t.mu.Lock()
-	defer t.mu.Unlock()
 	active := make([]BackgroundTask, 0, len(t.active))
 	for _, task := range t.active {
 		active = append(active, cloneBackgroundTask(*task))
 	}
 	recent := make([]BackgroundTask, 0, len(t.recent))
+	db := t.db
+	limit := t.maxRecent
+	if limit < 1 {
+		limit = 30
+	}
 	for _, task := range t.recent {
 		recent = append(recent, cloneBackgroundTask(task))
 	}
+	t.mu.Unlock()
+	if db != nil {
+		var rows []model.BackgroundTaskRecord
+		if err := db.Where("status <> ?", TaskStatusRunning).Order("started_at DESC").Limit(limit).Find(&rows).Error; err == nil {
+			recent = make([]BackgroundTask, 0, len(rows))
+			for _, row := range rows {
+				recent = append(recent, backgroundTaskFromRecord(row))
+			}
+		} else if t.log != nil {
+			t.log.Warn("load background task history failed; using memory history", zap.Error(err))
+		}
+	}
 	return TaskSnapshot{Active: active, Recent: recent}
 }
 
+func backgroundTaskFromRecord(row model.BackgroundTaskRecord) BackgroundTask {
+	task := BackgroundTask{
+		ID: row.ID, Kind: row.Kind, Name: row.Name, Status: row.Status,
+		Stage: row.Stage, SourcePath: row.SourcePath, DestPath: row.DestPath,
+		Message: row.Message, Error: row.Error, StartedAt: row.StartedAt,
+		UpdatedAt: row.UpdatedAt, FinishedAt: row.FinishedAt,
+	}
+	_ = json.Unmarshal([]byte(row.Details), &task.Details)
+	_ = json.Unmarshal([]byte(row.Metrics), &task.Metrics)
+	_ = json.Unmarshal([]byte(row.Items), &task.Items)
+	return task
+}
+
 func (t *TaskTrackerService) update(id string, update TaskUpdate) {
 	now := t.currentTime()
 	t.mu.Lock()
@@ -155,6 +211,7 @@ func (t *TaskTrackerService) update(id string, update TaskUpdate) {
 	applyTaskUpdate(task, update)
 	task.UpdatedAt = now
 	snapshot := cloneBackgroundTask(*task)
+	t.persist(snapshot)
 	t.mu.Unlock()
 	t.publish(snapshot)
 }
@@ -186,6 +243,7 @@ func (t *TaskTrackerService) finish(id string, err error, update TaskUpdate) {
 		t.recent = t.recent[:t.maxRecent]
 	}
 	notifier := t.failureNotifier
+	t.persist(snapshot)
 	t.mu.Unlock()
 	t.publish(snapshot)
 
@@ -195,6 +253,26 @@ func (t *TaskTrackerService) finish(id string, err error, update TaskUpdate) {
 	}
 }
 
+func (t *TaskTrackerService) persist(task BackgroundTask) {
+	if t == nil || t.db == nil {
+		return
+	}
+	encode := func(value any) string {
+		data, _ := json.Marshal(value)
+		return string(data)
+	}
+	row := model.BackgroundTaskRecord{
+		ID: task.ID, Kind: task.Kind, Name: task.Name, Status: task.Status,
+		Stage: task.Stage, SourcePath: task.SourcePath, DestPath: task.DestPath,
+		Message: task.Message, Error: task.Error, Details: encode(task.Details),
+		Metrics: encode(task.Metrics), Items: encode(task.Items), StartedAt: task.StartedAt,
+		UpdatedAt: task.UpdatedAt, FinishedAt: task.FinishedAt,
+	}
+	if err := t.db.Save(&row).Error; err != nil && t.log != nil {
+		t.log.Warn("persist background task failed", zap.String("task_id", task.ID), zap.Error(err))
+	}
+}
+
 // SetFailureNotifier 注入任务失败时的管理员通知回调。
 func (t *TaskTrackerService) SetFailureNotifier(fn func(ctx context.Context, text string)) {
 	if t == nil {

internal/service/task_tracker_persistence_test.go

@@ -0,0 +1,78 @@
+package service
+
+import (
+	"fmt"
+	"sync"
+	"testing"
+
+	"go.uber.org/zap"
+
+	"github.com/truewhile/MeBox/internal/model"
+)
+
+func TestTaskTrackerPersistsHistoryAcrossRestart(t *testing.T) {
+	db := newServiceTestDB(t)
+	tracker := NewTaskTrackerService(zap.NewNop(), nil)
+	tracker.SetPersistence(db)
+	task := tracker.Start(TaskKindScan, "scan", TaskUpdate{Details: []string{"initial detail"}})
+	task.Update(TaskUpdate{Metrics: map[string]int64{"visited": 42}})
+	task.Finish(nil, TaskUpdate{Message: "done"})
+	restarted := NewTaskTrackerService(zap.NewNop(), nil)
+	restarted.SetPersistence(db)
+	snapshot := restarted.Snapshot()
+	if len(snapshot.Active) != 0 || len(snapshot.Recent) != 1 {
+		t.Fatalf("unexpected history: %#v", snapshot)
+	}
+	recent := snapshot.Recent[0]
+	if recent.Status != TaskStatusCompleted || recent.Metrics["visited"] != 42 || len(recent.Details) != 1 || recent.FinishedAt == nil {
+		t.Fatalf("task history lost fields: %#v", recent)
+	}
+}
+
+func TestTaskTrackerConcurrentUpdatesDoNotRegressFinishedTasks(t *testing.T) {
+	db := newServiceTestDB(t)
+	sqlDB, err := db.DB()
+	if err != nil {
+		t.Fatal(err)
+	}
+	sqlDB.SetMaxOpenConns(1)
+	tracker := NewTaskTrackerService(zap.NewNop(), nil)
+	tracker.SetPersistence(db)
+	var workers sync.WaitGroup
+	for i := 0; i < 12; i++ {
+		workers.Add(1)
+		go func(index int) {
+			defer workers.Done()
+			task := tracker.Start(TaskKindScan, fmt.Sprintf("scan-%d", index), TaskUpdate{})
+			task.Update(TaskUpdate{Metrics: map[string]int64{"visited": 1}})
+			task.Finish(nil, TaskUpdate{})
+			task.Update(TaskUpdate{Message: "late update"})
+			_ = tracker.Snapshot()
+		}(i)
+	}
+	workers.Wait()
+	var completed int64
+	if err := db.Model(&model.BackgroundTaskRecord{}).Where("status = ?", TaskStatusCompleted).Count(&completed).Error; err != nil || completed != 12 {
+		t.Fatalf("finished task status regressed: completed=%d err=%v", completed, err)
+	}
+	if snapshot := tracker.Snapshot(); len(snapshot.Active) != 0 || len(snapshot.Recent) != 12 {
+		t.Fatalf("inconsistent task snapshot: %#v", snapshot)
+	}
+}
+
+func TestTaskTrackerMarksAbandonedTasksInterrupted(t *testing.T) {
+	db := newServiceTestDB(t)
+	tracker := NewTaskTrackerService(zap.NewNop(), nil)
+	tracker.SetPersistence(db)
+	tracker.Start(TaskKindOrganize, "unfinished", TaskUpdate{})
+	restarted := NewTaskTrackerService(zap.NewNop(), nil)
+	restarted.SetPersistence(db)
+	snapshot := restarted.Snapshot()
+	if len(snapshot.Recent) != 1 || snapshot.Recent[0].Status != TaskStatusInterrupted || snapshot.Recent[0].FinishedAt == nil {
+		t.Fatalf("abandoned task not marked interrupted: %#v", snapshot)
+	}
+	var running int64
+	if err := db.Model(&model.BackgroundTaskRecord{}).Where("status = ?", TaskStatusRunning).Count(&running).Error; err != nil || running != 0 {
+		t.Fatalf("stale running tasks: %d err=%v", running, err)
+	}
+}

internal/service/token_svc.go

@@ -170,8 +170,16 @@ func (s *TokenService) storeRefreshToken(ctx context.Context, rt *model.RefreshT
 	if err := s.repo.RefreshToken.Create(ctx, rt); err != nil {
 		return err
 	}
-	if err := s.repo.RefreshToken.RevokeOldestActiveByUserID(ctx, rt.UserID, s.maxActiveRefreshTokens(ctx)); err != nil && s.log != nil {
-		s.log.Warn("failed to enforce refresh token session limit", zap.String("user_id", rt.UserID), zap.Error(err))
+	// 「最大同时登录终端」只约束未绑定设备会话的旧客户端。
+	//
+	// 移动端每台设备有独立认证会话，刷新令牌归属该会话；如果仍按用户统一
+	// 裁剪活跃令牌，第 N+1 台设备登录（或任一设备刷新）就会把最早那台设备
+	// 的刷新令牌标记为已撤销，那台设备下次刷新收到 SESSION_REVOKED，被迫
+	// 重新登录。设备数量由设备策略单独约束，不能靠撤销刷新令牌实现。
+	if rt.AuthSessionID == "" {
+		if err := s.repo.RefreshToken.RevokeOldestActiveLegacyByUserID(ctx, rt.UserID, s.maxActiveRefreshTokens(ctx)); err != nil && s.log != nil {
+			s.log.Warn("failed to enforce refresh token session limit", zap.String("user_id", rt.UserID), zap.Error(err))
+		}
 	}
 	return nil
 }

internal/service/transcoder.go

@@ -1,7 +1,8 @@
 // Package service — HLS on-demand transcoder.
 //
 // TranscoderService spawns ffmpeg processes that segment a source media file
-// into HLS (.m3u8 + .ts). The output lives under cache.cache_dir/hls/<id>.
+// into HLS (.m3u8 + .ts). Each playback scope owns a cache directory and
+// every ffmpeg run writes to its own run-* subdirectory.
 // The HTTP layer serves these files directly with a normal http.FileServer.
 //
 // Encoder selection (read once at startup from the config):
@@ -15,9 +16,11 @@
 //	                         plus the kernel module loaded)
 //
 // Concurrency model:
-//   - Each Media has at most one active ffmpeg job.
-//   - jobs[mediaID] tracks the running goroutine + cancel func.
-//   - Calling Start while a job already exists is a no-op.
+//   - Each authenticated user/player scope has at most one active ffmpeg job.
+//   - jobs[jobKey] tracks the running goroutine + cancel func; mediaID remains
+//     the actual media identity for database access and activity reporting.
+//   - Legacy internal callers keep media-keyed behaviour.
+//   - Equivalent requests within one scope reuse the current output.
 //   - When the playlist file appears on disk we consider the job "ready"
 //     and unblock the HTTP handler that was waiting on it.
 package service
@@ -49,9 +52,10 @@ type TranscoderService struct {
 
 	mu   sync.Mutex
 	jobs map[string]*hlsJob
-	// startGates serializes EnsureJobFrom / StopJob per media so concurrent
-	// playlist hits cannot spawn multiple ffmpeg writers into one HLS dir.
-	startGates  sync.Map // mediaID -> *sync.Mutex
+	// Start gates are reference-counted so random playback session keys do not
+	// accumulate after their last starter/stopper has left.
+	startGateMu sync.Mutex
+	startGates  map[string]*hlsStartGate
 	strmResolve func(ctx context.Context, raw string) (*StrmPlayResult, error)
 	probe       *FFprobeService
 
@@ -66,6 +70,7 @@ type TranscoderService struct {
 
 // hlsJob holds the live state of one ffmpeg run.
 type hlsJob struct {
+	jobKey     string
 	mediaID    string
 	outputDir  string
 	cancel     context.CancelFunc
@@ -156,14 +161,19 @@ func (t *TranscoderService) transcodeConfig() *config.Config {
 	}
 }
 
-// HLSDir is the per-media directory that holds index.m3u8 + segment files.
-func (t *TranscoderService) HLSDir(mediaID string) string {
-	return filepath.Join(t.cfg.Cache.CacheDir, "hls", mediaID)
+// HLSDir is the cache root for one internal playback job key.
+func (t *TranscoderService) HLSDir(jobKey string) string {
+	return filepath.Join(t.cfg.Cache.CacheDir, "hls", jobKey)
 }
 
 // PlaylistPath returns the absolute path of the m3u8 playlist for a media.
-func (t *TranscoderService) PlaylistPath(mediaID string) string {
-	return filepath.Join(t.HLSDir(mediaID), "index.m3u8")
+func (t *TranscoderService) PlaylistPath(jobKey string) string {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if job := t.jobs[jobKey]; job != nil {
+		return t.jobPlaylistPath(job)
+	}
+	return filepath.Join(t.HLSDir(jobKey), "index.m3u8")
 }
 
 // EnsureJob makes sure a transcode is running for mediaID from the start of
@@ -194,7 +204,8 @@ func (t *TranscoderService) EnsureJobFromSubtitle(ctx context.Context, mediaID s
 
 // EnsureJobFromSubtitleQuality is EnsureJobFromSubtitle with an explicit local
 // HLS quality profile. Empty qualityID keeps the global transcoder config.
-func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, mediaID string, startSec float64, seekGen int64, subtitleStream int, qualityID string) (string, error) {
+func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, mediaID string, startSec float64, seekGen int64, subtitleStream int, qualityID string, scopes ...HLSPlaybackScope) (string, error) {
+	jobKey := hlsPlaybackJobKey(mediaID, scopes)
 	cfg := t.transcodeConfig()
 	if !cfg.Transcoder.Enabled {
 		return "", ErrTranscodeDisabled
@@ -219,28 +230,31 @@ func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, me
 		return "", ErrMediaNotFound
 	}
 
-	gate := t.mediaStartGate(mediaID)
-	gate.Lock()
-	defer gate.Unlock()
+	unlock := t.lockJobStart(jobKey)
+	defer unlock()
 
 	t.mu.Lock()
-	if existing, ok := t.jobs[mediaID]; ok {
+	if existing, ok := t.jobs[jobKey]; ok {
 		reusable := true
+		playlist := t.jobPlaylistPath(existing)
 		if existing.completed {
-			info, err := os.Stat(t.PlaylistPath(mediaID))
+			info, err := os.Stat(playlist)
 			reusable = err == nil && info.Size() > 0
 		}
 		if reusable && sameHLSConfiguration(existing, startSec, subtitleStream, qualityID) {
-			t.touchJobLocked(mediaID)
+			if seekGen > existing.seekGen {
+				existing.seekGen = seekGen
+			}
+			t.touchJobLocked(jobKey)
 			t.mu.Unlock()
-			return t.PlaylistPath(mediaID), nil
+			return playlist, nil
 		}
 		if reusable && !shouldReplaceHLSJobConfigurationQuality(existing, startSec, seekGen, subtitleStream, qualityID) {
-			t.touchJobLocked(mediaID)
+			t.touchJobLocked(jobKey)
 			t.mu.Unlock()
-			return t.PlaylistPath(mediaID), nil
+			return playlist, nil
 		}
-		prev := t.detachJobLocked(mediaID)
+		prev := t.detachJobLocked(jobKey)
 		t.mu.Unlock()
 		waitJobExit(prev, 12*time.Second)
 	} else {
@@ -258,6 +272,9 @@ func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, me
 	input.Quality = quality
 	t.maybeFillDuration(ctx, m, input)
 	settings := ffmpegArgSettingsFromConfig(cfg, quality)
+	// 「原画」档位遇到浏览器可解的 H.264 源时只换封装，避免慢机器上重编码
+	// 追不上播放（两核软件编码实测 0.1～0.2 倍速）。其它档位要改分辨率，仍重编码。
+	input.CopyVideo = t.remuxEligible(ctx, m, quality, subtitleStream)
 	jobEncoder := settings.encoder
 	if settings.noScale || subtitleStream >= 0 {
 		jobEncoder = ""
@@ -267,12 +284,23 @@ func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, me
 		return "", err
 	}
 
-	outDir := t.HLSDir(mediaID)
-	// Wipe prior segments so a mid-file restart cannot serve stale early chunks.
-	// Only safe after the previous ffmpeg has exited (waited above / via gate).
-	if err := resetHLSDir(outDir); err != nil {
+	rootDir := t.HLSDir(jobKey)
+	// Runs use distinct directories even when Windows keeps an old segment
+	// open. A delayed request can never read a newer run's seg_00000.ts.
+	if err := resetHLSDir(rootDir); err != nil {
 		return "", err
 	}
+	outDir, err := os.MkdirTemp(rootDir, "run-")
+	if err != nil {
+		return "", err
+	}
+	registered := false
+	defer func() {
+		if !registered {
+			_ = os.RemoveAll(outDir)
+			_ = os.Remove(rootDir)
+		}
+	}()
 
 	t.mu.Lock()
 	if max := t.maxConcurrent(); max > 0 && t.runningJobCountLocked() >= max {
@@ -287,7 +315,11 @@ func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, me
 	if subtitleStream >= 0 {
 		jobEncoder = "software (subtitle burn-in)"
 	}
+	if input.CopyVideo {
+		jobEncoder = remuxEncoderLabel
+	}
 	job := &hlsJob{
+		jobKey:         jobKey,
 		mediaID:        mediaID,
 		outputDir:      outDir,
 		cancel:         cancel,
@@ -302,7 +334,8 @@ func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, me
 		ffmpegPath:     bin,
 		config:         cfg,
 	}
-	t.jobs[mediaID] = job
+	t.jobs[jobKey] = job
+	registered = true
 	t.mu.Unlock()
 
 	helper.Go(t.log, "transcoder.monitorIdle", func() { t.monitorIdle(jobCtx, job) })
@@ -310,7 +343,7 @@ func (t *TranscoderService) EnsureJobFromSubtitleQuality(ctx context.Context, me
 		defer close(job.done)
 		t.runFFmpeg(jobCtx, job, input)
 	})
-	return t.PlaylistPath(mediaID), nil
+	return filepath.Join(outDir, "index.m3u8"), nil
 }
 
 // shouldReplaceHLSJob reports whether an incoming playlist request may cancel
@@ -357,9 +390,33 @@ func sameHLSConfiguration(existing *hlsJob, startSec float64, subtitleStream int
 		sameHLSStart(existing.startSec, startSec)
 }
 
-func (t *TranscoderService) mediaStartGate(mediaID string) *sync.Mutex {
-	v, _ := t.startGates.LoadOrStore(mediaID, &sync.Mutex{})
-	return v.(*sync.Mutex)
+type hlsStartGate struct {
+	mu    sync.Mutex
+	users int
+}
+
+func (t *TranscoderService) lockJobStart(key string) func() {
+	t.startGateMu.Lock()
+	if t.startGates == nil {
+		t.startGates = make(map[string]*hlsStartGate)
+	}
+	gate := t.startGates[key]
+	if gate == nil {
+		gate = &hlsStartGate{}
+		t.startGates[key] = gate
+	}
+	gate.users++
+	t.startGateMu.Unlock()
+	gate.mu.Lock()
+	return func() {
+		gate.mu.Unlock()
+		t.startGateMu.Lock()
+		gate.users--
+		if gate.users == 0 {
+			delete(t.startGates, key)
+		}
+		t.startGateMu.Unlock()
+	}
 }
 
 // detachJobLocked cancels and removes a job from the map without waiting.

internal/service/transcoder_ffmpeg_args.go

@@ -16,6 +16,9 @@ type transcodeInput struct {
 	StartSec       float64
 	SubtitleStream *int
 	Quality        *LocalHLSQuality
+	// CopyVideo 为 true 时视频流只换封装（-c:v copy），不重编码。
+	// 仅当源视频是浏览器可解的老三样（H.264/8bit/4:2:0）且不需要缩放时启用。
+	CopyVideo bool
 }
 
 type ffmpegArgSettings struct {
@@ -52,6 +55,7 @@ func buildFFmpegArgsForInput(cfg *config.Config, input transcodeInput, playlist,
 		// 原画档位不做硬件缩放的兼容处理，直接走软件编码，保持源分辨率。
 		settings.encoder = ""
 	}
+	copyVideo := input.CopyVideo && input.SubtitleStream == nil
 	video := ffmpegVideoPlanForSettings(settings)
 	if input.SubtitleStream != nil {
 		// Bitmap subtitles must be composited in software. Keeping CUDA/QSV/
@@ -60,13 +64,17 @@ func buildFFmpegArgsForInput(cfg *config.Config, input transcodeInput, playlist,
 		settings.encoder = ""
 		video = ffmpegVideoPlanForSettings(settings)
 	}
+	if copyVideo {
+		// 直通：不做缩放、不挂滤镜、不选编码器，整条视频流原样塞进 TS。
+		video = ffmpegVideoPlan{codec: "copy"}
+	}
 
 	// Mid-file restarts must not use -re: output -ss would otherwise crawl to the
 	// seek point at 1x wall-clock before emitting the first HLS segment.
 	realtime := settings.realtime && input.StartSec <= 0.05
 	args := baseFFmpegArgs(video.preInput, realtime)
-	args = appendInputAndVideoArgs(args, input, settings, video)
-	args = appendOutputHLSArgs(args, settings, segments, playlist)
+	args = appendInputAndVideoArgs(args, input, settings, video, copyVideo)
+	args = appendOutputHLSArgs(args, settings, segments, playlist, copyVideo)
 	return args
 }
 
@@ -161,7 +169,7 @@ func baseFFmpegArgs(preInput string, realtime bool) []string {
 	return args
 }
 
-func appendInputAndVideoArgs(args []string, input transcodeInput, settings ffmpegArgSettings, video ffmpegVideoPlan) []string {
+func appendInputAndVideoArgs(args []string, input transcodeInput, settings ffmpegArgSettings, video ffmpegVideoPlan, copyVideo bool) []string {
 	args = append(args, ffmpegHTTPInputArgs(input)...)
 	ss := ""
 	if input.StartSec > 0.05 {
@@ -172,6 +180,11 @@ func appendInputAndVideoArgs(args []string, input transcodeInput, settings ffmpe
 	// scrubbing; CDNs with Range support jump via demuxer seek instead.
 	if ss != "" {
 		args = append(args, "-ss", ss)
+		if copyVideo {
+			// 复制视频流时 ffmpeg 不能解码，精确 seek 会把关键帧之前的分组丢掉，
+			// 输出从 P 帧开始（花屏）。退到前一个关键帧，最多提前一两秒。
+			args = append(args, "-noaccurate_seek")
+		}
 	}
 	args = append(args, "-i", input.Source)
 	if input.SubtitleStream != nil {
@@ -197,7 +210,23 @@ func appendInputAndVideoArgs(args []string, input transcodeInput, settings ffmpe
 	return args
 }
 
-func appendOutputHLSArgs(args []string, settings ffmpegArgSettings, segments, playlist string) []string {
+func appendOutputHLSArgs(args []string, settings ffmpegArgSettings, segments, playlist string, copyVideo bool) []string {
+	if copyVideo {
+		// 视频是复制进来的，编码参数一律不适用；只保留音频转 AAC 与切片参数。
+		// -avoid_negative_ts 让带 B 帧的源在 -ss 之后不会出现负时间戳。
+		return append(args,
+			"-avoid_negative_ts", "make_zero",
+			"-c:a", "aac",
+			"-ar", "48000",
+			"-b:a", "128k",
+			"-ac", "2",
+			"-f", "hls",
+			"-hls_time", fmt.Sprintf("%d", settings.segmentSeconds),
+			"-hls_list_size", "0",
+			"-hls_segment_filename", segments,
+			playlist,
+		)
+	}
 	return append(args,
 		"-pix_fmt", "yuv420p",
 		"-b:v", settings.bitrate,

internal/service/transcoder_ffmpeg_probe.go

@@ -49,16 +49,18 @@ func (t *TranscoderService) runFFmpeg(ctx context.Context, job *hlsJob, input tr
 
 	t.mu.Lock()
 	// Only update the map entry if we are still the registered generation.
-	if cur, ok := t.jobs[job.mediaID]; ok && cur == job {
+	if cur, ok := t.jobs[job.key()]; ok && cur == job {
 		if err == nil && ctx.Err() == nil {
 			job.completed = true
 		} else {
-			delete(t.jobs, job.mediaID)
+			delete(t.jobs, job.key())
 		}
 	}
 	t.mu.Unlock()
 	if err != nil || ctx.Err() != nil {
 		job.cancel()
+		_ = os.RemoveAll(job.outputDir)
+		_ = os.Remove(filepath.Dir(job.outputDir)) // Remove the scope root only if empty.
 	}
 
 	t.hub.Publish("transcode", map[string]any{

internal/service/transcoder_jobs.go

@@ -26,16 +26,18 @@ func (t *TranscoderService) WaitReady(ctx context.Context, mediaID string, timeo
 		job, ok := t.jobs[mediaID]
 		var started time.Time
 		var completed bool
+		var playlist string
 		if ok {
 			started = job.startedAt
 			completed = job.completed
+			playlist = t.jobPlaylistPath(job)
 		}
 		t.mu.Unlock()
 		if !ok {
 			return false // A failed/exited job cannot become ready later.
 		}
 		if ok {
-			if info, err := os.Stat(t.PlaylistPath(mediaID)); err == nil {
+			if info, err := os.Stat(playlist); err == nil {
 				// Allow a small clock skew; reject anything older than this job.
 				if !info.ModTime().Before(started.Add(-2 * time.Second)) {
 					t.mu.Lock()
@@ -66,9 +68,8 @@ func (t *TranscoderService) WaitReady(ctx context.Context, mediaID string, timeo
 // briefly for it to exit so a subsequent EnsureJobFrom cannot race-write the
 // same HLS directory.
 func (t *TranscoderService) StopJob(mediaID string) {
-	gate := t.mediaStartGate(mediaID)
-	gate.Lock()
-	defer gate.Unlock()
+	unlock := t.lockJobStart(mediaID)
+	defer unlock()
 
 	t.mu.Lock()
 	prev := t.detachJobLocked(mediaID)
@@ -170,7 +171,7 @@ func (t *TranscoderService) monitorIdle(ctx context.Context, job *hlsJob) {
 			return
 		case <-ticker.C:
 			t.mu.Lock()
-			current, ok := t.jobs[job.mediaID]
+			current, ok := t.jobs[job.key()]
 			if !ok || current != job {
 				t.mu.Unlock()
 				return
@@ -185,11 +186,10 @@ func (t *TranscoderService) monitorIdle(ctx context.Context, job *hlsJob) {
 }
 
 func (t *TranscoderService) stopIdleJob(job *hlsJob, timeout time.Duration) bool {
-	gate := t.mediaStartGate(job.mediaID)
-	gate.Lock()
-	defer gate.Unlock()
+	unlock := t.lockJobStart(job.key())
+	defer unlock()
 	t.mu.Lock()
-	current := t.jobs[job.mediaID]
+	current := t.jobs[job.key()]
 	if current != job {
 		t.mu.Unlock()
 		return true
@@ -199,9 +199,12 @@ func (t *TranscoderService) stopIdleJob(job *hlsJob, timeout time.Duration) bool
 		t.mu.Unlock()
 		return false
 	}
-	t.detachJobLocked(job.mediaID)
+	t.detachJobLocked(job.key())
 	t.mu.Unlock()
 	waitJobExit(job, 12*time.Second)
+	if job.jobKey != "" {
+		_ = os.RemoveAll(t.HLSDir(job.key()))
+	}
 	t.log.Info("transcode idle timeout", zap.String("media_id", job.mediaID),
 		zap.Duration("idle_for", idleFor), zap.Duration("timeout", timeout))
 	return true

internal/service/transcoder_remux.go

@@ -0,0 +1,102 @@
+package service
+
+import (
+	"context"
+	"encoding/json"
+	"strings"
+
+	"github.com/truewhile/MeBox/internal/model"
+)
+
+// 蓝光原盘（m2ts，40 Mbps 级别）在两核小机器上重编码只有 0.1～0.2 倍速，HLS
+// 永远追不上播放，播放器等不到切片就报「转码失败」。当源视频本身就是浏览器
+// 能解的 H.264 / 8bit / 4:2:0，且用户选的是「原画」档位（不改分辨率）时，
+// 这里改走只换封装（-c:v copy）的直通路径：视频不重编码，音频转 AAC，
+// CPU 占用接近于零，起播时间从几十秒降到几秒。
+//
+// 直通只对「原画」生效。1080P/720P/480P 档位意味着要改分辨率，必须重新编码；
+// 那类请求仍然按原来的 libx264 路径处理（慢，但码率可控）。
+
+// remuxEncoderLabel 是直通任务在日志与任务面板里的标签。
+const remuxEncoderLabel = "remux"
+
+// remuxEligible 判断这次请求能否复制视频流而不是重编码。
+func (t *TranscoderService) remuxEligible(ctx context.Context, m *model.Media, quality *LocalHLSQuality, subtitleStream int) bool {
+	if t == nil || t.repo == nil || m == nil {
+		return false
+	}
+	// 烧录图形字幕要把字幕叠加进画面，必须解码+重编码。
+	if subtitleStream >= 0 {
+		return false
+	}
+	if !remuxAppliesToQuality(quality) {
+		return false
+	}
+	probe, err := t.repo.MediaProbe.Get(ctx, m.ID)
+	if err != nil || probe == nil {
+		// 没有探测缓存就无法确认档次/像素格式，保守走重编码。
+		return false
+	}
+	return remuxCopyableHeight(probe) > 0
+}
+
+// remuxAppliesToQuality 只放行「原画」档位（Height 为 0，即不缩放）。
+// quality 为 nil 表示调用方没有指定档位（走全局 max_height），同样不直通，
+// 否则会绕过配置的分辨率上限给出一个远超预期的码流。
+func remuxAppliesToQuality(quality *LocalHLSQuality) bool {
+	return quality != nil && quality.Height <= 0
+}
+
+// remuxCopyableHeight 在源视频可直接复制进 HLS 时返回它的高度，否则返回 0。
+func remuxCopyableHeight(probe *model.MediaProbe) int {
+	if probe == nil || probe.Height <= 0 {
+		return 0
+	}
+	if !strings.EqualFold(strings.TrimSpace(probe.VideoCodec), "h264") {
+		return 0
+	}
+	if !browserSafeH264Payload(probe.Payload) {
+		return 0
+	}
+	return probe.Height
+}
+
+// probePayloadStreams 只解析落库 payload 里与直通判断有关的字段。
+type probePayloadStreams struct {
+	Streams []struct {
+		Type    string `json:"type"`
+		Profile string `json:"profile"`
+		PixFmt  string `json:"pix_fmt"`
+	} `json:"streams"`
+}
+
+// browserSafeH264Payload 只放行 8bit 4:2:0 的 Baseline/Main/High。
+// Hi10P（High 10）和 4:2:2 母带浏览器解不出来，复制过去只会黑屏或无声。
+func browserSafeH264Payload(payload string) bool {
+	payload = strings.TrimSpace(payload)
+	if payload == "" {
+		// 老数据没有 payload：已经有 codec + 分辨率，按 8bit 常规情况处理。
+		return true
+	}
+	var parsed probePayloadStreams
+	if err := json.Unmarshal([]byte(payload), &parsed); err != nil {
+		return false
+	}
+	for _, stream := range parsed.Streams {
+		if !strings.EqualFold(strings.TrimSpace(stream.Type), "video") {
+			continue
+		}
+		switch strings.ToLower(strings.TrimSpace(stream.Profile)) {
+		case "", "constrained baseline", "baseline", "main", "high":
+		default:
+			return false
+		}
+		switch strings.ToLower(strings.TrimSpace(stream.PixFmt)) {
+		case "", "yuv420p", "yuvj420p":
+		default:
+			return false
+		}
+		return true
+	}
+	return true
+}

internal/service/transcoder_remux_test.go

@@ -0,0 +1,170 @@
+package service
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/truewhile/MeBox/internal/config"
+	"github.com/truewhile/MeBox/internal/model"
+)
+
+// 直通档位必须真的把视频流复制过去：一旦又带上 libx264 / -vf / 码率参数，
+// 慢机器上的「原画」就还是几十秒起播。
+func TestBuildFFmpegArgsRemuxCopiesVideoStream(t *testing.T) {
+	cfg := &config.Config{}
+	cfg.Transcoder.SegmentSeconds = 4
+	cfg.Transcoder.Realtime = true
+	cfg.Transcoder.Threads = 2
+	cfg.Transcoder.MaxHeight = 720
+
+	quality, ok := LocalHLSQualityByID("source")
+	if !ok {
+		t.Fatal("source quality missing")
+	}
+	args := buildFFmpegArgsForInput(cfg, transcodeInput{
+		Source:    "https://cdn.example/x.m2ts",
+		Headers:   map[string]string{"User-Agent": "MeBox-115-GoClient/1.0"},
+		StartSec:  52.4,
+		Quality:   &quality,
+		CopyVideo: true,
+	}, "/cache/hls/k/run-1/index.m3u8", "/cache/hls/k/run-1/seg_%05d.ts")
+	joined := strings.Join(args, " ")
+
+	for _, want := range []string{
+		"-c:v copy",
+		"-c:a aac",
+		"-ar 48000",
+		"-b:a 128k",
+		"-ac 2",
+		"-avoid_negative_ts make_zero",
+		"-ss 52.400",
+		"-noaccurate_seek",
+		"-hls_time 4",
+		"-hls_segment_filename /cache/hls/k/run-1/seg_%05d.ts",
+	} {
+		if !strings.Contains(joined, want) {
+			t.Errorf("remux args missing %q: %s", want, joined)
+		}
+	}
+	for _, unwanted := range []string{
+		"libx264",
+		"-vf ",
+		"-b:v",
+		"-maxrate",
+		"-bufsize",
+		"-force_key_frames",
+		"-preset",
+		"-threads",
+		"-pix_fmt",
+	} {
+		if strings.Contains(joined, unwanted) {
+			t.Errorf("remux args must not contain %q: %s", unwanted, joined)
+		}
+	}
+	// 中途起播不能加 -re，否则会先按 1 倍速爬到目标位置才出第一个切片。
+	if strings.Contains(joined, " -re ") {
+		t.Errorf("mid-file remux must not use -re: %s", joined)
+	}
+}
+
+// 烧录图形字幕要把字幕叠进画面，必须解码重编码，不能被直通标志绕过。
+func TestBuildFFmpegArgsRemuxIgnoredForSubtitleBurnIn(t *testing.T) {
+	cfg := &config.Config{}
+	cfg.Transcoder.MaxHeight = 720
+	cfg.Transcoder.SegmentSeconds = 4
+
+	quality, _ := LocalHLSQualityByID("source")
+	subtitle := 4
+	args := buildFFmpegArgsForInput(cfg, transcodeInput{
+		Source:         "/media/ep.mkv",
+		Quality:        &quality,
+		CopyVideo:      true,
+		SubtitleStream: &subtitle,
+	}, "/o/x.m3u8", "/o/seg_%05d.ts")
+	joined := strings.Join(args, " ")
+
+	if strings.Contains(joined, "-c:v copy") {
+		t.Fatalf("subtitle burn-in must not copy the video stream: %s", joined)
+	}
+	if !strings.Contains(joined, "libx264") || !strings.Contains(joined, "-filter_complex") {
+		t.Fatalf("subtitle burn-in should re-encode: %s", joined)
+	}
+	if strings.Contains(joined, "-noaccurate_seek") {
+		t.Fatalf("encoded path should keep accurate seek: %s", joined)
+	}
+}
+
+// 只有「原画」档位（不缩放）可以直通；其它档位要改分辨率。
+func TestRemuxAppliesToQuality(t *testing.T) {
+	if remuxAppliesToQuality(nil) {
+		t.Fatal("nil quality must not remux: it falls back to the configured max height")
+	}
+	source, _ := LocalHLSQualityByID("source")
+	if !remuxAppliesToQuality(&source) {
+		t.Fatal("source quality should remux")
+	}
+	for _, id := range []string{"1080", "720", "480"} {
+		quality, ok := LocalHLSQualityByID(id)
+		if !ok {
+			t.Fatalf("quality %s missing", id)
+		}
+		if remuxAppliesToQuality(&quality) {
+			t.Fatalf("quality %s must re-encode", id)
+		}
+	}
+}
+
+// 只有 8bit 4:2:0 的 H.264 能安全复制；Hi10P / 4:2:2 / HEVC 复制过去浏览器黑屏。
+func TestRemuxCopyableHeight(t *testing.T) {
+	const blurayPayload = `{"container":"mpegts","duration_sec":1451,"bit_rate":42609934,"streams":[{"index":0,"type":"video","codec":"h264","profile":"High","width":1920,"height":1080,"pix_fmt":"yuv420p","frame_rate":"23.976"},{"index":1,"type":"audio","codec":"pcm_bluray","channels":2}]}`
+
+	cases := []struct {
+		name  string
+		probe *model.MediaProbe
+		want  int
+	}{
+		{
+			name:  "bluray h264 8bit 420",
+			probe: &model.MediaProbe{VideoCodec: "h264", Height: 1080, Payload: blurayPayload},
+			want:  1080,
+		},
+		{
+			name:  "no payload falls back to codec and height",
+			probe: &model.MediaProbe{VideoCodec: "h264", Height: 720},
+			want:  720,
+		},
+		{
+			name:  "hevc cannot be copied into browser hls",
+			probe: &model.MediaProbe{VideoCodec: "hevc", Height: 1080, Payload: `{"streams":[{"type":"video","profile":"Main 10","pix_fmt":"yuv420p10le"}]}`},
+			want:  0,
+		},
+		{
+			name:  "hi10p h264 is unplayable in browsers",
+			probe: &model.MediaProbe{VideoCodec: "h264", Height: 1080, Payload: `{"streams":[{"type":"video","profile":"High 10","pix_fmt":"yuv420p10le"}]}`},
+			want:  0,
+		},
+		{
+			name:  "4:2:2 h264 is unplayable in browsers",
+			probe: &model.MediaProbe{VideoCodec: "h264", Height: 1080, Payload: `{"streams":[{"type":"video","profile":"High 4:2:2","pix_fmt":"yuv422p"}]}`},
+			want:  0,
+		},
+		{
+			name:  "missing probe",
+			probe: nil,
+			want:  0,
+		},
+		{
+			name:  "unknown height",
+			probe: &model.MediaProbe{VideoCodec: "h264", Height: 0, Payload: blurayPayload},
+			want:  0,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := remuxCopyableHeight(tc.probe); got != tc.want {
+				t.Fatalf("remuxCopyableHeight() = %d, want %d", got, tc.want)
+			}
+		})
+	}
+}

web/src/api/backup.ts

@@ -0,0 +1,28 @@
+import { api, LONG_REQUEST_TIMEOUT } from './client'
+
+export interface BackupInfo {
+  filename: string
+  size: number
+  created_at: string
+  automatic: boolean
+}
+
+export const backupAPI = {
+  list: () => api.get<{ items: BackupInfo[] }>('/admin/backups').then((r) => r.data.items ?? []),
+  create: () => api.post<BackupInfo>('/admin/backups', {}, { timeout: LONG_REQUEST_TIMEOUT }).then((r) => r.data),
+  remove: (filename: string) => api.delete('/admin/backups', { params: { filename } }),
+  restore: (filename: string) => api.post<{ message: string; restart_required: boolean }>('/admin/backups/restore', null, { params: { filename }, timeout: LONG_REQUEST_TIMEOUT }).then((r) => r.data),
+  download: async (filename: string) => {
+    const response = await api.get<Blob>('/admin/backups/download', {
+      params: { filename },
+      responseType: 'blob',
+      timeout: LONG_REQUEST_TIMEOUT,
+    })
+    const url = URL.createObjectURL(response.data)
+    const anchor = document.createElement('a')
+    anchor.href = url
+    anchor.download = filename
+    anchor.click()
+    URL.revokeObjectURL(url)
+  },
+}

web/src/api/client.ts

@@ -175,7 +175,7 @@ export function streamURL(mediaId: string, options: { proxy?: boolean } = {}): s
 
 // hlsURL returns the m3u8 playlist URL fed into hls.js.
 // startSec > 0 asks the server to (re)start ffmpeg from that source offset.
-export function hlsURL(mediaId: string, startSec = 0, subtitleStream?: number, quality?: string): string {
+export function hlsURL(mediaId: string, startSec = 0, subtitleStream?: number, quality?: string, sessionID?: string): string {
   const safeStart = Math.max(0, Math.round(startSec * 1000) / 1000)
   // Always send start= (including 0) so the server can tell an intentional
   // restart-from-head apart from a missing query on a stale refresh.
@@ -188,7 +188,8 @@ export function hlsURL(mediaId: string, startSec = 0, subtitleStream?: number, q
       ? `&subtitle=${encodeURIComponent(String(subtitleStream))}`
       : ''
   const qualityQuery = quality ? `&quality=${encodeURIComponent(quality)}` : ''
-  return `/api/hls/${encodeURIComponent(mediaId)}/index.m3u8?${tokenQuery()}${profileQuery()}${start}${subtitle}${qualityQuery}${bust}`
+  const session = sessionID ? `&session_id=${encodeURIComponent(sessionID)}` : ''
+  return `/api/hls/${encodeURIComponent(mediaId)}/index.m3u8?${tokenQuery()}${profileQuery()}${start}${subtitle}${qualityQuery}${bust}${session}`
 }
 
 // cloudHlsURL returns the MeBox-proxied 115 cloud HLS master playlist URL.
@@ -202,8 +203,9 @@ export function cloudHlsURL(mediaId: string, definition: string): string {
 
 // Stop an on-demand HLS job. keepalive makes the request survive page
 // navigation/tab close, where an axios promise can be discarded by browsers.
-export function stopHLSJob(mediaId: string): void {
-  const url = `/api/hls/${encodeURIComponent(mediaId)}?${tokenQuery()}${profileQuery()}`
+export function stopHLSJob(mediaId: string, sessionID?: string): void {
+  const session = sessionID ? `&session_id=${encodeURIComponent(sessionID)}` : ''
+  const url = `/api/hls/${encodeURIComponent(mediaId)}?${tokenQuery()}${profileQuery()}${session}`
   void fetch(url, {
     method: 'DELETE',
     credentials: 'same-origin',

web/src/api/library.ts

@@ -262,7 +262,15 @@ export const mediaAPI = {
       })
       .then((r) => r.data),
 
-  searchPage: (q: string, page = 1, pageSize = 50, options?: { groupVersions?: boolean; groupSeries?: boolean }) =>
+  searchPage: (q: string, page = 1, pageSize = 50, options?: {
+    groupVersions?: boolean
+    groupSeries?: boolean
+    libraryId?: string
+    yearMin?: number
+    yearMax?: number
+    genres?: string[]
+    sort?: 'title_asc' | 'year_desc' | 'rating_desc'
+  }) =>
     api
       .get<MediaSearchPage>('/media', {
         params: {
@@ -271,6 +279,11 @@ export const mediaAPI = {
           page_size: pageSize,
           group_versions: options?.groupVersions === false ? 0 : undefined,
           ...(options?.groupSeries ? { group_series: 1 } : {}),
+          ...(options?.libraryId ? { library_id: options.libraryId } : {}),
+          ...(options?.yearMin ? { year_min: options.yearMin } : {}),
+          ...(options?.yearMax ? { year_max: options.yearMax } : {}),
+          ...(options?.genres?.length ? { genre: options.genres } : {}),
+          ...(options?.sort ? { sort: options.sort } : {}),
         },
         timeout: LONG_REQUEST_TIMEOUT,
       })

web/src/api/quality.ts

@@ -0,0 +1,16 @@
+import { api } from './client'
+import type { Media } from '../types'
+
+export type MediaQualityIssue = 'missing' | 'unmatched' | 'poster'
+
+export interface MediaQualityRow {
+  issue: MediaQualityIssue
+  media: Media
+}
+
+export const qualityAPI = {
+  list: (issue: MediaQualityIssue, page = 1, pageSize = 50) =>
+    api.get<{ items: MediaQualityRow[]; total: number; page: number; page_size: number }>('/admin/quality', {
+      params: { issue, page, page_size: pageSize },
+    }).then((r) => r.data),
+}

web/src/api/reader.ts

@@ -249,6 +249,8 @@ export const readerAPI = {
   deleteSource: (id: string) => api.delete(`/reader/sources/${id}`),
   debugSource: (id: string, key: string) =>
     api.post<{ logs: string[] }>(`/reader/sources/${id}/debug`, { key }, longOpts).then((r) => r.data.logs),
+  smokeSource: (id: string, key: string) =>
+    api.post<{ logs: string[] }>(`/reader/sources/${id}/debug`, { key }, { timeout: 60_000 }).then((r) => r.data.logs),
 
   // ── 书源登录与源变量 ──
   // 取登录界面描述（loginUi 控件 + 已保存值 + 当前 Cookie 状态）

web/src/api/tasks.ts

@@ -0,0 +1,27 @@
+import { api } from './client'
+
+export interface BackgroundTask {
+  id: string
+  kind: string
+  name: string
+  status: 'running' | 'completed' | 'failed' | 'interrupted' | string
+  stage?: string
+  source_path?: string
+  dest_path?: string
+  message?: string
+  error?: string
+  details?: string[]
+  metrics?: Record<string, number>
+  started_at: string
+  updated_at: string
+  finished_at?: string
+}
+
+export interface TaskSnapshot {
+  active: BackgroundTask[]
+  recent: BackgroundTask[]
+}
+
+export const tasksAPI = {
+  snapshot: () => api.get<TaskSnapshot>('/admin/tasks').then((r) => r.data),
+}

web/src/appRoutes.tsx

@@ -50,6 +50,8 @@ const StrmUploadQueuePage = lazy(() =>
 )
 const ScraperQueuePage = lazy(() => import('./pages/ScraperQueuePage').then((m) => ({ default: m.ScraperQueuePage })))
 const TaskQueuePage = lazy(() => import('./pages/TaskQueuePage').then((m) => ({ default: m.TaskQueuePage })))
+const MediaQualityPage = lazy(() => import('./pages/MediaQualityPage').then((m) => ({ default: m.MediaQualityPage })))
+const SetupWizardPage = lazy(() => import('./pages/SetupWizardPage').then((m) => ({ default: m.SetupWizardPage })))
 
 // 常用页面的路由 chunk 空闲预取：应用加载完成后浏览器一空闲就把浏览路径
 // （库列表/库详情/媒体详情/收藏/历史等）的 chunk 拉下来，
@@ -125,5 +127,7 @@ export const appRoutes: AppRoute[] = [
   { path: 'strm/uploads', element: <StrmUploadQueuePage />, adminOnly: true },
   { path: 'scraper/queue', element: <ScraperQueuePage />, adminOnly: true },
   { path: 'queue', element: <TaskQueuePage />, adminOnly: true },
+  { path: 'quality', element: <MediaQualityPage />, adminOnly: true },
+  { path: 'setup', element: <SetupWizardPage />, adminOnly: true },
   { path: 'admin', element: <AdminPage />, adminOnly: true },
 ]

web/src/components/MediaCard.tsx

@@ -89,6 +89,11 @@ export const MediaCard = memo(function MediaCard({
               <span>{displayRating.toFixed(1)}</span>
             </span>
           )}
+          {media.availability_state === 'missing' && (
+            <span className="absolute left-2 top-2 rounded-lg border border-amber-300/30 bg-[#111827]/90 px-2 py-1 text-[10px] font-bold text-amber-300 shadow-sm">
+              文件失联
+            </span>
+          )}
 
           {/* Premium Hover Overlay（CSS 过渡替代 framer-motion 逐卡动画实例） */}
           <div className={`absolute inset-0 bg-gradient-to-t from-[#111827]/90 via-[#111827]/30 to-transparent opacity-0 group-hover:opacity-100 transition-opacity duration-300 flex flex-col justify-end ${

web/src/components/RequireAuth.tsx

@@ -1,13 +1,20 @@
-import { useEffect, type ReactNode } from 'react'
+import { Fragment, useEffect, type ReactNode } from 'react'
 import { Navigate, useLocation } from 'react-router-dom'
 
 import { useAuthStore } from '../stores/auth'
+import { usePlayProfileStore } from '../stores/playProfile'
+import { libraryCacheScope } from '../utils/libraryCache'
 import { hydrateReaderSettings, startReaderSettingsSync } from '../utils/readerSettingsSync'
 
 // Route guard: redirects to /login when no token is present.
 export function RequireAuth({ children }: { children: ReactNode }) {
   const token = useAuthStore((s) => s.token)
   const userId = useAuthStore((s) => s.user?.id ?? null)
+  // Drop local page state and in-flight callbacks when visibility changes.
+  useAuthStore((s) => s.user)
+  usePlayProfileStore((s) => s.activeProfileId)
+  usePlayProfileStore((s) => s.activeProfilePinToken)
+  const visibilityKey = libraryCacheScope()
   const location = useLocation()
 
   // 阅读器偏好按账号存在服务端：一进入受保护区域就开启回写订阅，并在
@@ -23,7 +30,7 @@ export function RequireAuth({ children }: { children: ReactNode }) {
   if (!token) {
     return <Navigate to="/login" replace state={{ from: location }} />
   }
-  return <>{children}</>
+  return <Fragment key={visibilityKey}>{children}</Fragment>
 }
 
 // Route guard: only allows users with role === "admin".