Merge pull request #32 from truewhile/cursor/fix-emby-hero-backdrop

修复 Emby 大海报在剧集图缓存被淘汰后显示占位图

cmd/server/main_test.go

@@ -76,6 +76,9 @@ func TestServeSPAServesAssetsImmutableAndBypassesAPIRoutes(t *testing.T) {
 	if err := os.MkdirAll(filepath.Join(webDir, "assets"), 0o755); err != nil {
 		t.Fatal(err)
 	}
+	if err := os.MkdirAll(filepath.Join(webDir, "fonts"), 0o755); err != nil {
+		t.Fatal(err)
+	}
 	if err := os.MkdirAll(filepath.Join(webDir, "brand"), 0o755); err != nil {
 		t.Fatal(err)
 	}
@@ -85,6 +88,9 @@ func TestServeSPAServesAssetsImmutableAndBypassesAPIRoutes(t *testing.T) {
 	if err := os.WriteFile(filepath.Join(webDir, "assets", "app.js"), []byte("console.log('ok')"), 0o644); err != nil {
 		t.Fatal(err)
 	}
+	if err := os.WriteFile(filepath.Join(webDir, "fonts", "geist-400.woff2"), []byte("wOF2-test-font"), 0o644); err != nil {
+		t.Fatal(err)
+	}
 	if err := os.WriteFile(filepath.Join(webDir, "brand", "mebox-logo.svg"), []byte("<svg></svg>"), 0o644); err != nil {
 		t.Fatal(err)
 	}
@@ -105,6 +111,29 @@ func TestServeSPAServesAssetsImmutableAndBypassesAPIRoutes(t *testing.T) {
 		t.Fatalf("asset Cache-Control = %q, want immutable", got)
 	}
 
+	fontReq := httptest.NewRequest(http.MethodGet, "/fonts/geist-400.woff2", nil)
+	fontResp := httptest.NewRecorder()
+	router.ServeHTTP(fontResp, fontReq)
+	if fontResp.Code != http.StatusOK {
+		t.Fatalf("font status = %d, want 200", fontResp.Code)
+	}
+	if got := fontResp.Header().Get("Cache-Control"); !strings.Contains(got, "max-age=86400") {
+		t.Fatalf("font Cache-Control = %q, want max-age=86400", got)
+	}
+	if got := fontResp.Body.String(); got != "wOF2-test-font" {
+		t.Fatalf("font body = %q, want wOF2-test-font", got)
+	}
+
+	missingFontReq := httptest.NewRequest(http.MethodGet, "/fonts/missing.woff2", nil)
+	missingFontResp := httptest.NewRecorder()
+	router.ServeHTTP(missingFontResp, missingFontReq)
+	if missingFontResp.Code != http.StatusNotFound {
+		t.Fatalf("missing font status = %d, want 404", missingFontResp.Code)
+	}
+	if strings.Contains(missingFontResp.Body.String(), "index") {
+		t.Fatalf("missing font should not serve SPA index: %q", missingFontResp.Body.String())
+	}
+
 	brandReq := httptest.NewRequest(http.MethodGet, "/brand/mebox-logo.svg", nil)
 	brandResp := httptest.NewRecorder()
 	router.ServeHTTP(brandResp, brandReq)

cmd/server/router.go

@@ -59,6 +59,13 @@ func serveSPA(r *gin.Engine, root fs.FS) {
 		c.Next()
 	})
 	assets.GET("/*filepath", serveFSDir(root, "assets"))
+	fonts := r.Group("/fonts")
+	fonts.Use(middleware.GzipStatic())
+	fonts.Use(func(c *gin.Context) {
+		c.Header("Cache-Control", "public, max-age=86400")
+		c.Next()
+	})
+	fonts.GET("/*filepath", serveFSDir(root, "fonts"))
 	brand := r.Group("/brand")
 	brand.Use(func(c *gin.Context) {
 		setNoCacheHeaders(c)
@@ -70,11 +77,11 @@ func serveSPA(r *gin.Engine, root fs.FS) {
 		r.GET(rootFile, serveFSFile(root, name))
 		r.HEAD(rootFile, serveFSFile(root, name))
 	}
-		r.NoRoute(middleware.GzipStatic(), func(c *gin.Context) {
-			if handler.TryHandleEmbyNormalizedRoute(c, r) {
-				return
-			}
-			path := c.Request.URL.Path
+	r.NoRoute(middleware.GzipStatic(), func(c *gin.Context) {
+		if handler.TryHandleEmbyNormalizedRoute(c, r) {
+			return
+		}
+		path := c.Request.URL.Path
 		if shouldBypassSPAFallback(path) {
 			c.Status(http.StatusNotFound)
 			return

go.mod

@@ -20,6 +20,7 @@ require (
 	go.uber.org/zap v1.27.0
 	golang.org/x/crypto v0.49.0
 	golang.org/x/image v0.37.0
+	golang.org/x/sync v0.20.0
 	golang.org/x/sys v0.42.0
 	golang.org/x/time v0.15.0
 	gopkg.in/yaml.v3 v3.0.1
@@ -88,7 +89,6 @@ require (
 	golang.org/x/arch v0.25.0 // indirect
 	golang.org/x/exp v0.0.0-20251023183803-a4bb9ffd2546 // indirect
 	golang.org/x/net v0.52.0 // indirect
-	golang.org/x/sync v0.20.0 // indirect
 	golang.org/x/text v0.35.0 // indirect
 	google.golang.org/protobuf v1.36.11 // indirect
 	gopkg.in/ini.v1 v1.67.0 // indirect

internal/config/defaults.go

@@ -48,6 +48,7 @@ func setDefaults(v *viper.Viper) {
 	v.SetDefault("cache.redis_url", "")
 	v.SetDefault("cache.redis_prefix", "mebox")
 	v.SetDefault("cache.media_ttl_seconds", 90)
+	v.SetDefault("cache.emby_latest_ttl_seconds", 300)
 
 	v.SetDefault("search.backend", "")
 	v.SetDefault("search.opensearch_url", "")

internal/config/types.go

@@ -124,6 +124,11 @@ type CacheConfig struct {
 	RedisURL           string `mapstructure:"redis_url"`
 	RedisPrefix        string `mapstructure:"redis_prefix"`
 	MediaTTLSeconds    int    `mapstructure:"media_ttl_seconds"`
+	// EmbyLatestTTLSeconds 是 Emby「最新添加」(Items/Latest) 的缓存时长。
+	// 客户端刷新首页时会并发请求全部媒体库的 Latest（生产环境观察到 73 个
+	// 并发），缓存过短会让这批请求同时穿透并各自重建 payload，在低配主机
+	// 上造成秒级延迟。默认 300 秒，新入库内容最迟 5 分钟后出现在最新列表。
+	EmbyLatestTTLSeconds int `mapstructure:"emby_latest_ttl_seconds"`
 }
 
 type SearchConfig struct {

internal/handler/danmaku.go

@@ -3,6 +3,7 @@ package handler
 
 import (
 	"net/http"
+	"strings"
 
 	"github.com/gin-gonic/gin"
 
@@ -14,7 +15,13 @@ import (
 // specific danmaku library chosen by the user after a disambiguation.
 func getDanmakuHandler(svc *service.Container) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		res, err := svc.Danmaku.Fetch(c.Request.Context(), c.Param("id"), c.Query("kw"), c.Query("episodeId"))
+		uid := currentUserID(c)
+		// 弹幕合并偏好按用户存储：这里读取后作为本次抓取的选项传入。
+		opts := service.DanmakuFetchOptions{
+			MergeSources: svc.Danmaku.MergeSourcesEnabled(c.Request.Context(), uid),
+		}
+		res, err := svc.Danmaku.FetchWithOptions(
+			c.Request.Context(), c.Param("id"), c.Query("kw"), c.Query("episodeId"), opts)
 		if err != nil {
 			c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
 			return
@@ -28,6 +35,34 @@ func getDanmakuHandler(svc *service.Container) gin.HandlerFunc {
 // admin privileges.
 func getDanmakuConfigHandler(svc *service.Container) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		c.JSON(http.StatusOK, svc.Danmaku.Config(c.Request.Context()))
+		c.JSON(http.StatusOK, svc.Danmaku.ConfigForUser(c.Request.Context(), currentUserID(c)))
+	}
+}
+
+// updateDanmakuSettingsHandler 持久化当前用户的弹幕偏好。目前只有合并开关，
+// 落在 user 表上（与字幕简繁偏好同样按用户存储）。
+func updateDanmakuSettingsHandler(svc *service.Container) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		uid := currentUserID(c)
+		if strings.TrimSpace(uid) == "" {
+			c.JSON(http.StatusUnauthorized, gin.H{"error": "not authenticated"})
+			return
+		}
+		var req struct {
+			MergeSources *bool `json:"merge_sources"`
+		}
+		if err := c.ShouldBindJSON(&req); err != nil {
+			c.JSON(http.StatusBadRequest, gin.H{"error": "invalid body"})
+			return
+		}
+		if req.MergeSources == nil {
+			c.JSON(http.StatusBadRequest, gin.H{"error": "merge_sources is required"})
+			return
+		}
+		if err := svc.Danmaku.SetMergeSources(c.Request.Context(), uid, *req.MergeSources); err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+			return
+		}
+		c.JSON(http.StatusOK, gin.H{"merge_sources": *req.MergeSources})
 	}
 }

internal/handler/danmaku_settings_test.go

@@ -0,0 +1,135 @@
+package handler
+
+import (
+	"bytes"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/glebarez/sqlite"
+	"go.uber.org/zap"
+	"gorm.io/gorm"
+
+	"github.com/truewhile/MeBox/internal/middleware"
+	"github.com/truewhile/MeBox/internal/model"
+	"github.com/truewhile/MeBox/internal/repository"
+	"github.com/truewhile/MeBox/internal/service"
+)
+
+// newDanmakuSettingsContext 构造带登录用户的最小 gin 上下文。
+func newDanmakuSettingsContext(t *testing.T, svc *service.Container, method, path, body string, userID string) (*gin.Context, *httptest.ResponseRecorder) {
+	t.Helper()
+	gin.SetMode(gin.TestMode)
+	w := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(w)
+	c.Request = httptest.NewRequest(method, path, bytes.NewBufferString(body))
+	c.Request.Header.Set("Content-Type", "application/json")
+	if userID != "" {
+		c.Set(middleware.CtxUserID, userID)
+	}
+	return c, w
+}
+
+func newDanmakuSettingsService(t *testing.T) *service.Container {
+	t.Helper()
+	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
+	if err != nil {
+		t.Fatalf("open db: %v", err)
+	}
+	if err := db.AutoMigrate(&model.Setting{}, &model.Media{}, &model.User{}); err != nil {
+		t.Fatalf("migrate: %v", err)
+	}
+	repos := repository.New(db)
+	user := model.User{Username: "settings-user", PasswordHash: "x", Role: "user", IsActive: true}
+	user.ID = "user-1"
+	if err := repos.User.Create(t.Context(), &user); err != nil {
+		t.Fatalf("create user: %v", err)
+	}
+	return &service.Container{
+		Repo:    repos,
+		Danmaku: service.NewDanmakuService(zap.NewNop(), repos),
+	}
+}
+
+func TestUpdateDanmakuSettingsPersistsMergeSources(t *testing.T) {
+	svc := newDanmakuSettingsService(t)
+
+	c, w := newDanmakuSettingsContext(t, svc, http.MethodPut, "/danmaku/settings",
+		`{"merge_sources":true}`, "user-1")
+	updateDanmakuSettingsHandler(svc)(c)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200 (body=%s)", w.Code, w.Body.String())
+	}
+	var resp struct {
+		MergeSources bool `json:"merge_sources"`
+	}
+	if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
+		t.Fatalf("decode: %v", err)
+	}
+	if !resp.MergeSources {
+		t.Fatal("response should echo merge_sources=true")
+	}
+	// 落库校验：重新读取应为 true。
+	if !svc.Danmaku.MergeSourcesEnabled(t.Context(), "user-1") {
+		t.Fatal("merge preference was not persisted")
+	}
+}
+
+func TestUpdateDanmakuSettingsRejectsMissingField(t *testing.T) {
+	svc := newDanmakuSettingsService(t)
+
+	c, w := newDanmakuSettingsContext(t, svc, http.MethodPut, "/danmaku/settings", `{}`, "user-1")
+	updateDanmakuSettingsHandler(svc)(c)
+
+	if w.Code != http.StatusBadRequest {
+		t.Fatalf("status = %d, want 400 (body=%s)", w.Code, w.Body.String())
+	}
+}
+
+func TestUpdateDanmakuSettingsRequiresAuthentication(t *testing.T) {
+	svc := newDanmakuSettingsService(t)
+
+	c, w := newDanmakuSettingsContext(t, svc, http.MethodPut, "/danmaku/settings",
+		`{"merge_sources":true}`, "")
+	updateDanmakuSettingsHandler(svc)(c)
+
+	if w.Code != http.StatusUnauthorized {
+		t.Fatalf("status = %d, want 401 (body=%s)", w.Code, w.Body.String())
+	}
+}
+
+// config 接口应把当前用户的合并偏好带出去，供面板初始化。
+func TestGetDanmakuConfigIncludesPerUserMergePreference(t *testing.T) {
+	svc := newDanmakuSettingsService(t)
+
+	c, w := newDanmakuSettingsContext(t, svc, http.MethodGet, "/danmaku/config", "", "user-1")
+	getDanmakuConfigHandler(svc)(c)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200", w.Code)
+	}
+	var cfg struct {
+		MergeSources bool `json:"merge_sources"`
+	}
+	if err := json.Unmarshal(w.Body.Bytes(), &cfg); err != nil {
+		t.Fatalf("decode: %v", err)
+	}
+	if cfg.MergeSources {
+		t.Fatal("default merge preference should be false")
+	}
+
+	if err := svc.Danmaku.SetMergeSources(t.Context(), "user-1", true); err != nil {
+		t.Fatalf("set: %v", err)
+	}
+	c2, w2 := newDanmakuSettingsContext(t, svc, http.MethodGet, "/danmaku/config", "", "user-1")
+	getDanmakuConfigHandler(svc)(c2)
+	if err := json.Unmarshal(w2.Body.Bytes(), &cfg); err != nil {
+		t.Fatalf("decode: %v", err)
+	}
+	if !cfg.MergeSources {
+		t.Fatal("config should reflect the persisted merge preference")
+	}
+}

internal/handler/emby_compat_additions_test.go

@@ -0,0 +1,121 @@
+package handler
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"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/model"
+	"github.com/truewhile/MeBox/internal/repository"
+	"github.com/truewhile/MeBox/internal/service"
+)
+
+// newEmbyCompatTestRouter 构造一个挂载了完整 Emby 路由表的测试引擎。
+func newEmbyCompatTestRouter(t *testing.T, secret string) *gin.Engine {
+	t.Helper()
+	gin.SetMode(gin.TestMode)
+	db, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
+	if err != nil {
+		t.Fatalf("open db: %v", err)
+	}
+	if err := db.AutoMigrate(model.AllModels()...); err != nil {
+		t.Fatalf("migrate: %v", err)
+	}
+	repos := repository.New(db)
+	if err := repos.User.Create(t.Context(), &model.User{
+		Base:         model.Base{ID: "user-1"},
+		Username:     "tester",
+		PasswordHash: "x",
+		Role:         "admin",
+		Tier:         "plus",
+		IsActive:     true,
+	}); err != nil {
+		t.Fatalf("create user: %v", err)
+	}
+	router := gin.New()
+	registerEmbyRoutes(router, secret, &service.Container{
+		Repo: repos,
+		Emby: service.NewEmbyService(&config.Config{}, zap.NewNop(), repos),
+	})
+	return router
+}
+
+func TestEmbyAdditionalPartsReturnsEmptyArray(t *testing.T) {
+	const secret = "test-secret"
+	router := newEmbyCompatTestRouter(t, secret)
+
+	req := httptest.NewRequest(http.MethodGet, "/emby/Videos/msgo-series-abc/AdditionalParts", nil)
+	req.Header.Set("X-Emby-Token", signedTestToken(t, secret))
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200 (body=%s)", w.Code, w.Body.String())
+	}
+	// 必须命中 AdditionalParts 静态路由并返回空数组，而不是被 /Videos/:id/:seg
+	// 的 HLS 兜底路由接走返回空 404。
+	var payload []any
+	if err := json.Unmarshal(w.Body.Bytes(), &payload); err != nil {
+		t.Fatalf("decode body %q: %v", w.Body.String(), err)
+	}
+	if len(payload) != 0 {
+		t.Fatalf("expected an empty array, got %v", payload)
+	}
+}
+
+func TestEmbyItemImagesWithoutTypeReturnsArray(t *testing.T) {
+	router := newEmbyCompatTestRouter(t, "test-secret")
+
+	// 不带 Type 的图片清单接口是公开路由，不要求 token，与带 Type 的
+	// 图片字节流一致（客户端缓存 URL 时会丢 token）。
+	req := httptest.NewRequest(http.MethodGet, "/emby/Items/unknown-item/Images", nil)
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200 (body=%s)", w.Code, w.Body.String())
+	}
+	if ct := w.Header().Get("Content-Type"); ct == "" || ct[:16] != "application/json" {
+		t.Fatalf("content type = %q, want application/json", ct)
+	}
+	var payload []any
+	if err := json.Unmarshal(w.Body.Bytes(), &payload); err != nil {
+		t.Fatalf("decode body %q: %v", w.Body.String(), err)
+	}
+}
+
+func TestEmbyItemImagesLowerCaseRouteIsRegistered(t *testing.T) {
+	router := newEmbyCompatTestRouter(t, "test-secret")
+
+	req := httptest.NewRequest(http.MethodGet, "/emby/items/unknown-item/images", nil)
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200 (body=%s)", w.Code, w.Body.String())
+	}
+}
+
+func TestEmbyUserImageWithoutAvatarReturnsCacheableNotFound(t *testing.T) {
+	router := newEmbyCompatTestRouter(t, "test-secret")
+
+	req := httptest.NewRequest(http.MethodGet, "/emby/Users/user-1/Images/Primary", nil)
+	w := httptest.NewRecorder()
+	router.ServeHTTP(w, req)
+
+	// 用户没有头像时 Emby 同样返回 404，但响应必须可缓存，否则客户端会
+	// 在每次进入设置页时重复请求（线上曾观察到每分钟一次的重试）。
+	if w.Code != http.StatusNotFound {
+		t.Fatalf("status = %d, want 404 (body=%s)", w.Code, w.Body.String())
+	}
+	if cc := w.Header().Get("Cache-Control"); cc != "public, max-age=86400" {
+		t.Fatalf("Cache-Control = %q, want the cacheable directive", cc)
+	}
+}

internal/handler/emby_images.go

@@ -50,6 +50,49 @@ func embyItemImageHandler(svc *service.Container) gin.HandlerFunc {
 	}
 }
 
+// embyItemImagesHandler 处理不带 Type 的 GET /Items/{Id}/Images，返回图片
+// 清单（Emby 的 ImageInfo 数组）。客户端据此决定详情页加载哪些图。
+func embyItemImagesHandler(svc *service.Container) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		id := strings.TrimSpace(c.Param("id"))
+		if svc == nil || svc.Emby == nil || id == "" {
+			c.JSON(http.StatusOK, []any{})
+			return
+		}
+		infos := svc.Emby.ImageInfos(c.Request.Context(), id)
+		if infos == nil {
+			infos = []map[string]any{}
+		}
+		c.JSON(http.StatusOK, infos)
+	}
+}
+
+// embyUserImageHandler 处理 /Users/{UserId}/Images/{Type}。Emby 对未设置
+// 头像的用户同样返回 404，但响应必须带缓存头，否则客户端每次进入设置页
+// 都会重复请求同一个空头像（日志中曾观察到每分钟重试）。
+func embyUserImageHandler(svc *service.Container) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		uid := strings.TrimSpace(c.Param("userId"))
+		raw := ""
+		if svc != nil && svc.Emby != nil && uid != "" {
+			raw = svc.Emby.UserAvatarURL(c.Request.Context(), uid)
+		}
+		if raw == "" || svc == nil || svc.ImageProxy == nil {
+			embyMissingAvatar(c)
+			return
+		}
+		if err := svc.ImageProxy.Serve(c.Request.Context(), c.Writer, c.Request, raw); err != nil {
+			embyMissingAvatar(c)
+		}
+	}
+}
+
+// embyMissingAvatar 以 Emby 语义返回"该用户没有头像"，并允许客户端长期缓存。
+func embyMissingAvatar(c *gin.Context) {
+	c.Header("Cache-Control", "public, max-age=86400")
+	c.Status(http.StatusNotFound)
+}
+
 func clearEmbyImageNoStoreHeaders(c *gin.Context) {
 	c.Writer.Header().Del("Cache-Control")
 	c.Writer.Header().Del("Pragma")

internal/handler/emby_routes.go

@@ -115,12 +115,24 @@ func registerEmbyPublicClientRoutes(grp *gin.RouterGroup, jwtSecret string, svc
 
 func registerEmbyPublicImageRoutes(grp *gin.RouterGroup, svc *service.Container) {
 	// 图片公开（Infuse 缓存 URL 时会丢 token）
+	//
+	// 不带 Type 的 /Items/{Id}/Images 返回图片清单（ImageInfo 数组），与下面
+	// 带 Type 的图片字节流是不同接口，必须单独注册，否则会落到 NoRoute 并
+	// 返回 text/plain 的 404。
+	grp.GET("/Items/:id/Images", embyItemImagesHandler(svc))
+	grp.HEAD("/Items/:id/Images", embyItemImagesHandler(svc))
+	grp.GET("/items/:id/images", embyItemImagesHandler(svc))
 	grp.GET("/Items/:id/Images/:type", embyItemImageHandler(svc))
 	grp.GET("/Items/:id/Images/:type/:index", embyItemImageHandler(svc))
 	grp.HEAD("/Items/:id/Images/:type", embyItemImageHandler(svc))
 	grp.GET("/items/:id/images/:type", embyItemImageHandler(svc))
 	grp.GET("/items/:id/images/:type/:index", embyItemImageHandler(svc))
 	grp.HEAD("/items/:id/images/:type", embyItemImageHandler(svc))
+	// 用户头像。没有头像时返回带缓存头的 404，避免客户端反复重试。
+	grp.GET("/Users/:userId/Images/:type", embyUserImageHandler(svc))
+	grp.HEAD("/Users/:userId/Images/:type", embyUserImageHandler(svc))
+	grp.GET("/users/:userId/images/:type", embyUserImageHandler(svc))
+	grp.HEAD("/users/:userId/images/:type", embyUserImageHandler(svc))
 }
 
 func registerEmbyGetRoutes(grp *gin.RouterGroup, svc *service.Container, paths []string, factory embyRouteHandlerFactory) {
@@ -202,6 +214,12 @@ func registerEmbyAuthenticatedPlaybackRoutes(auth *gin.RouterGroup, prefix strin
 	auth.POST("/Users/:userId/Items/:id/PlaybackInfo", embyPlaybackInfoHandler(svc))
 
 	registerEmbyVideoStreamRoutes(auth, svc, "/Videos")
+	// Emby 官方接口：附加片段清单。MeBox 不提供附加片段，但必须返回空数组
+	// 而不是 404 —— 部分客户端（RodelPlayer）在详情页无条件请求它，404 会
+	// 让它们把条目判定为不完整。必须注册成静态段，否则会被
+	// /Videos/:id/:seg 的 HLS 兜底路由抢先匹配并返回空 404。
+	auth.GET("/Videos/:id/AdditionalParts", embyEmptyArrayHandler(svc))
+	auth.HEAD("/Videos/:id/AdditionalParts", embyEmptyArrayHandler(svc))
 	auth.GET("/Videos/:id/Subtitles/:index/Stream", embySubtitleStreamHandler(svc))
 	auth.HEAD("/Videos/:id/Subtitles/:index/Stream", embySubtitleStreamHandler(svc))
 	auth.GET("/Users/:userId/Videos/:id/Subtitles/:index/Stream", embySubtitleStreamHandler(svc))

internal/handler/routes_authenticated_extras.go

@@ -12,6 +12,7 @@ func registerAuthedUISurfaceRoutes(authed *gin.RouterGroup, svc *service.Contain
 
 	authed.GET("/danmaku/:id", getDanmakuHandler(svc))
 	authed.GET("/danmaku/config", getDanmakuConfigHandler(svc))
+	authed.PUT("/danmaku/settings", updateDanmakuSettingsHandler(svc))
 
 	authed.GET("/watch-history", historyListHandler(svc))
 	authed.GET("/watch-history/stats", historyStatsHandler(svc))

internal/model/user.go

@@ -31,6 +31,10 @@ type User struct {
 	// SubtitleChineseMode 是网页播放器外挂字幕的简繁转换偏好：
 	// original / simplified / traditional。
 	SubtitleChineseMode string `gorm:"size:16;not null;default:original" json:"subtitle_chinese_mode"`
+	// DanmakuMergeSources 是网页播放器的弹幕偏好：开启后，同一集的多个弹幕
+	// 来源会被合并并按「时间 + 内容」去重后一起展示。按用户存储，避免一个
+	// 用户的开关影响其他人。
+	DanmakuMergeSources bool `gorm:"default:false" json:"danmaku_merge_sources"`
 	// ExpiredAt is the account expiry time. Nil means the account never
 	// expires. When set and in the past, the account is treated as expired
 	// (login blocked) until an admin or a redemption code renews it.

internal/repository/media_repository_upsert.go

@@ -3,6 +3,7 @@ package repository
 import (
 	"context"
 	"errors"
+	"path/filepath"
 	"strings"
 
 	"gorm.io/gorm"
@@ -10,6 +11,18 @@ import (
 	"github.com/truewhile/MeBox/internal/model"
 )
 
+// MediaUpsertItem carries a media row and optional sibling paths from an
+// earlier keep_ext naming mode. An alias is only used when the exact new path
+// does not exist in the database; in that case the existing row is migrated to
+// the new path so scraped metadata survives renames such as:
+//
+//	foo.strm -> foo.mkv.strm
+//	foo.mkv.strm -> foo.strm
+type MediaUpsertItem struct {
+	Media      *model.Media
+	AliasPaths []string
+}
+
 // Upsert inserts or updates a media row keyed by Path (unique index).
 //
 // 重要：当一条行已经存在时，scanner 重扫只应该刷新文件级元数据
@@ -22,20 +35,14 @@ import (
 //     显式写入）。这两个问题都让 EnrichLibrary(WHERE scrape_status='pending')
 //     永远捞不到数据。
 func (r *MediaRepository) Upsert(ctx context.Context, m *model.Media) error {
-	var indexIDs []string
-	err := withSQLiteBusyRetry(ctx, func() error {
-		id, uerr := r.upsertWithDB(ctx, r.db, m)
-		if uerr != nil {
-			return uerr
-		}
-		indexIDs = append(indexIDs[:0], id)
-		return nil
-	})
-	if err != nil {
-		return err
-	}
-	r.indexByIDBestEffort(ctx, indexIDs)
-	return nil
+	return r.UpsertWithAliases(ctx, m, nil)
+}
+
+// UpsertWithAliases is Upsert with explicit, filesystem-verified STRM sibling
+// aliases. It preserves the old row's ID, CreatedAt and scraped metadata while
+// moving it to the current path.
+func (r *MediaRepository) UpsertWithAliases(ctx context.Context, m *model.Media, aliasPaths []string) error {
+	return r.UpsertBatchWithAliases(ctx, []MediaUpsertItem{{Media: m, AliasPaths: aliasPaths}})
 }
 
 // UpsertBatch 在单个事务里逐条执行 Upsert：扫描一批只提交（fsync）一次，
@@ -46,6 +53,17 @@ func (r *MediaRepository) Upsert(ctx context.Context, m *model.Media) error {
 // 事务内会把 SQLite 写锁挂起在网络 IO 上，且批内用非事务连接回读只能
 // 拿到提交前的旧版本数据，把陈旧内容写进索引。
 func (r *MediaRepository) UpsertBatch(ctx context.Context, items []*model.Media) error {
+	mapped := make([]MediaUpsertItem, 0, len(items))
+	for _, item := range items {
+		if item != nil {
+			mapped = append(mapped, MediaUpsertItem{Media: item})
+		}
+	}
+	return r.UpsertBatchWithAliases(ctx, mapped)
+}
+
+// UpsertBatchWithAliases runs alias-aware upserts in one transaction.
+func (r *MediaRepository) UpsertBatchWithAliases(ctx context.Context, items []MediaUpsertItem) error {
 	if len(items) == 0 {
 		return nil
 	}
@@ -53,11 +71,11 @@ func (r *MediaRepository) UpsertBatch(ctx context.Context, items []*model.Media)
 	err := withSQLiteBusyRetry(ctx, func() error {
 		indexIDs = indexIDs[:0]
 		return r.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
-			for _, m := range items {
-				if m == nil {
+			for _, item := range items {
+				if item.Media == nil {
 					continue
 				}
-				id, err := r.upsertWithDB(ctx, tx, m)
+				id, err := r.upsertWithDB(ctx, tx, item.Media, item.AliasPaths)
 				if err != nil {
 					return err
 				}
@@ -87,9 +105,9 @@ func (r *MediaRepository) indexByIDBestEffort(ctx context.Context, ids []string)
 	}
 }
 
-// upsertWithDB 落库（新建或更新），返回需要重建索引的媒体 ID（无则空串）。
-func (r *MediaRepository) upsertWithDB(ctx context.Context, db *gorm.DB, m *model.Media) (string, error) {
-	existing, created, err := r.findOrCreateMediaByPath(ctx, db, m)
+// upsertWithDB 落库（新建、更新或从旧路径迁移），返回需要重建索引的媒体 ID。
+func (r *MediaRepository) upsertWithDB(ctx context.Context, db *gorm.DB, m *model.Media, aliasPaths []string) (string, error) {
+	existing, created, adopted, err := r.findOrCreateMediaByPath(ctx, db, m, aliasPaths)
 	if err != nil {
 		return "", err
 	}
@@ -98,6 +116,12 @@ func (r *MediaRepository) upsertWithDB(ctx context.Context, db *gorm.DB, m *mode
 	}
 
 	updates := mediaUpsertUpdates(existing, *m)
+	if adopted {
+		updates["path"] = m.Path
+		if existing.DeletedAt.Valid {
+			updates["deleted_at"] = nil
+		}
+	}
 	if len(updates) == 0 {
 		*m = existing
 		return "", nil
@@ -107,31 +131,67 @@ func (r *MediaRepository) upsertWithDB(ctx context.Context, db *gorm.DB, m *mode
 		return "", err
 	}
 	// 回写 ID / 不可变字段，让 caller 拿到完整的现有行。
+	if adopted {
+		existing.Path = m.Path
+		existing.DeletedAt = gorm.DeletedAt{}
+	}
 	*m = existing
 	return existing.ID, nil
 }
 
-func (r *MediaRepository) findOrCreateMediaByPath(ctx context.Context, db *gorm.DB, m *model.Media) (model.Media, bool, error) {
+func (r *MediaRepository) findOrCreateMediaByPath(ctx context.Context, db *gorm.DB, m *model.Media, aliasPaths []string) (model.Media, bool, bool, error) {
 	var existing model.Media
 	err := db.WithContext(ctx).Unscoped().Where("path = ?", m.Path).First(&existing).Error
 	if errors.Is(err, gorm.ErrRecordNotFound) {
+		if alias, aliasErr := r.findMediaByAlias(ctx, db, m.Path, aliasPaths); aliasErr == nil {
+			return alias, false, true, nil
+		} else if !errors.Is(aliasErr, gorm.ErrRecordNotFound) {
+			return model.Media{}, false, false, aliasErr
+		}
 		// 新行：保证 scrape_status 走 GORM default:pending（即留空让数据库填）。
 		if m.ScrapeStatus == "" {
 			m.ScrapeStatus = "pending"
 		}
 		if createErr := db.WithContext(ctx).Create(m).Error; createErr == nil {
-			return *m, true, nil
+			return *m, true, false, nil
 		} else if retryErr := db.WithContext(ctx).Unscoped().Where("path = ?", m.Path).First(&existing).Error; retryErr != nil {
-			return model.Media{}, false, createErr
+			return model.Media{}, false, false, createErr
 		} else {
 			// 并发插入竞态：重查已命中既有行，直接走更新分支。
-			return existing, false, nil
+			return existing, false, false, nil
 		}
 	}
 	if err != nil {
-		return model.Media{}, false, err
+		return model.Media{}, false, false, err
 	}
-	return existing, false, nil
+	return existing, false, false, nil
+}
+
+func (r *MediaRepository) findMediaByAlias(ctx context.Context, db *gorm.DB, currentPath string, aliasPaths []string) (model.Media, error) {
+	aliases := make([]string, 0, len(aliasPaths))
+	seen := make(map[string]struct{}, len(aliasPaths))
+	for _, alias := range aliasPaths {
+		alias = filepath.Clean(strings.TrimSpace(alias))
+		if alias == "" || alias == "." || alias == filepath.Clean(currentPath) {
+			continue
+		}
+		if _, ok := seen[alias]; ok {
+			continue
+		}
+		seen[alias] = struct{}{}
+		aliases = append(aliases, alias)
+	}
+	if len(aliases) == 0 {
+		return model.Media{}, gorm.ErrRecordNotFound
+	}
+	var existing model.Media
+	err := db.WithContext(ctx).Unscoped().
+		Where("path IN ?", aliases).
+		Order("CASE WHEN scrape_status = 'matched' THEN 0 ELSE 1 END ASC, " +
+			"CASE WHEN COALESCE(poster_url, '') <> '' OR COALESCE(overview, '') <> '' THEN 0 ELSE 1 END ASC, " +
+			"CASE WHEN deleted_at IS NULL THEN 0 ELSE 1 END ASC, updated_at DESC, created_at DESC").
+		First(&existing).Error
+	return existing, err
 }
 
 func mediaUpsertUpdates(existing, incoming model.Media) map[string]any {

internal/service/danmaku_episode_match_test.go

@@ -0,0 +1,140 @@
+package service
+
+import (
+	"testing"
+)
+
+func TestDanmakuEpisodeNumber(t *testing.T) {
+	cases := []struct {
+		in   string
+		want string
+	}{
+		{"第1话 裏切りの大空", "1"},
+		{"第18话 自己相似的两性同体-Fractal Androgynous-", "18"},
+		{"第11话", "11"},
+		{"【dandan&animeko】 第29集 那我们走吧", "29"},
+		{"第 202 集", "202"},
+		{"第1.5话 特别篇", "1.5"},
+		{"正片", ""},
+		{"", ""},
+	}
+	for _, tc := range cases {
+		if got := danmakuEpisodeNumber(tc.in); got != tc.want {
+			t.Errorf("danmakuEpisodeNumber(%q) = %q, want %q", tc.in, got, tc.want)
+		}
+	}
+}
+
+func TestDanmakuEpisodeSubtitle(t *testing.T) {
+	cases := []struct {
+		in   string
+		want string
+	}{
+		{"第1话 裏切りの大空", "裏切りの大空"},
+		{"第18话 自己相似的两性同体-Fractal Androgynous-", "自己相似的两性同体-Fractal Androgynous-"},
+		{"第11话", ""},
+		{"【dandan&animeko】 第29集 那我们走吧", "那我们走吧"},
+		{"正片", ""},
+	}
+	for _, tc := range cases {
+		if got := danmakuEpisodeSubtitle(tc.in); got != tc.want {
+			t.Errorf("danmakuEpisodeSubtitle(%q) = %q, want %q", tc.in, got, tc.want)
+		}
+	}
+}
+
+// 刮削信息匹配：优先使用本地已刮削的年份、集数和集标题，不能再被同名续作
+// 或缺少集标题的平台源抢走。
+func TestMatchScrapedDanmakuEpisodesUsesYearAndEpisodeTitle(t *testing.T) {
+	candidates := []DanmakuAnime{
+		{AnimeID: 1, AnimeTitle: "命运石之门 0(2018)【TV动画】from dandan&animeko", Episodes: []DanmakuEpisode{
+			{EpisodeID: 10299, EpisodeTitle: "【dandan&animeko】 第1话 零化域的缺失之环-Absolute Zero-"},
+		}},
+		{AnimeID: 2, AnimeTitle: "命运石之门(2011)【TV动画】from dandan&animeko", Episodes: []DanmakuEpisode{
+			{EpisodeID: 10322, EpisodeTitle: "【dandan&animeko】 第1话 始与终的序章-Turning Point-"},
+		}},
+		{AnimeID: 3, AnimeTitle: "命运石之门(2011)【动漫】from 360", Episodes: []DanmakuEpisode{
+			{EpisodeID: 10218, EpisodeTitle: "【qq】 第1集"},
+		}},
+	}
+
+	got := matchScrapedDanmakuEpisodes(candidates, "命运石之门", 2011, "1", "起始与终结的序章")
+	if len(got) != 1 {
+		t.Fatalf("matched %d anime, want 1: %#v", len(got), got)
+	}
+	if got[0].AnimeID != 2 || len(got[0].Episodes) != 1 || got[0].Episodes[0].EpisodeID != 10322 {
+		t.Fatalf("picked wrong source: %#v", got)
+	}
+}
+
+// 真实数据形态：官方 match 给出的剧名+集数在配置源里会命中多季/多版本，
+// 且顺序不可靠。必须靠副标题选中正确的那一集。
+func TestPickDanmakuEpisodeIDDisambiguatesBySubtitle(t *testing.T) {
+	// 实测样本：官方 match「命运石之门 第18话 自己相似的两性同体-…」，
+	// 配置源首条却是《命运石之门 0》的同一集号。
+	candidates := []DanmakuAnime{
+		{AnimeID: 1, AnimeTitle: "命运石之门 0(2018)", Episodes: []DanmakuEpisode{
+			{EpisodeID: 11072, EpisodeTitle: "【dandan&animeko】 第18话 并进对称的牵牛星-Translational"},
+		}},
+		{AnimeID: 2, AnimeTitle: "命运石之门(2011)", Episodes: []DanmakuEpisode{
+			{EpisodeID: 11095, EpisodeTitle: "【dandan&animeko】 第18话 自己相似的两性同体-Fractal Androgynous-"},
+		}},
+	}
+	got, ok := pickDanmakuEpisodeID(candidates, "18", "第18话 自己相似的两性同体-Fractal Androgynous-")
+	if !ok {
+		t.Fatal("expected a confident match")
+	}
+	if got != 11095 {
+		t.Fatalf("picked episodeId %d, want 11095 (first candidate is a different season)", got)
+	}
+}
+
+// 目标带副标题但没有任何候选的副标题对得上时，必须放弃而不是退回第一条，
+// 否则会给用户播放另一部番的弹幕。
+func TestPickDanmakuEpisodeIDRejectsWhenSubtitleNotFound(t *testing.T) {
+	candidates := []DanmakuAnime{
+		{AnimeID: 1, AnimeTitle: "某番 第一季", Episodes: []DanmakuEpisode{
+			{EpisodeID: 111, EpisodeTitle: "第3话 完全不同的标题"},
+		}},
+	}
+	if got, ok := pickDanmakuEpisodeID(candidates, "3", "第3话 期望的标题"); ok {
+		t.Fatalf("expected no match, got episodeId %d", got)
+	}
+}
+
+// 目标没有副标题（如「第11话」）时，退而要求集数一致；集数对不上同样放弃。
+func TestPickDanmakuEpisodeIDNumberOnlyFallback(t *testing.T) {
+	candidates := []DanmakuAnime{
+		{AnimeID: 1, AnimeTitle: "86 第二季", Episodes: []DanmakuEpisode{
+			// 该源对第二季采用绝对集号，第 11 集记作第 22 话。
+			{EpisodeID: 11113, EpisodeTitle: "第22话 辛"},
+		}},
+	}
+	if got, ok := pickDanmakuEpisodeID(candidates, "11", "第11话"); ok {
+		t.Fatalf("episode number mismatch must be rejected, got episodeId %d", got)
+	}
+
+	same := []DanmakuAnime{
+		{AnimeID: 1, AnimeTitle: "某番", Episodes: []DanmakuEpisode{
+			{EpisodeID: 222, EpisodeTitle: "第11话"},
+		}},
+	}
+	got, ok := pickDanmakuEpisodeID(same, "11", "第11话")
+	if !ok || got != 222 {
+		t.Fatalf("pickDanmakuEpisodeID = (%d,%v), want (222,true)", got, ok)
+	}
+}
+
+func TestPickDanmakuEpisodeIDSkipsInvalidIDs(t *testing.T) {
+	candidates := []DanmakuAnime{
+		{AnimeID: 1, AnimeTitle: "某番", Episodes: []DanmakuEpisode{
+			{EpisodeID: 0, EpisodeTitle: "第1话 目标"},
+			{EpisodeID: -5, EpisodeTitle: "第1话 目标"},
+			{EpisodeID: 333, EpisodeTitle: "第1话 目标"},
+		}},
+	}
+	got, ok := pickDanmakuEpisodeID(candidates, "1", "第1话 目标")
+	if !ok || got != 333 {
+		t.Fatalf("pickDanmakuEpisodeID = (%d,%v), want (333,true)", got, ok)
+	}
+}

internal/service/danmaku_match_test.go

@@ -105,27 +105,359 @@ func TestDanmakuFetchHashMatchLayer(t *testing.T) {
 	require.Contains(t, seen, `"matchMode":"hashAndFileName"`)
 }
 
-// 第 1 层拉弹幕：配置了自定义源时优先自定义源，失败才回退官方。
-func TestDanmakuFetchHashMatchUsesConfiguredSourceFirst(t *testing.T) {
+// 第 1 层拉弹幕：官方 match 给出的 episodeId 属于官方 ID 空间，不能直接拿去
+// 请求第三方源（真实源上只会 404）。必须用官方给到的剧名+集数在配置源里重定位
+// 到配置源自己的 episodeId，再用它拉弹幕。
+func TestDanmakuFetchHashMatchRemapsEpisodeIDToConfiguredSource(t *testing.T) {
 	videoPath, _ := writeDanmakuTestVideo(t, "测试动画.第01话.mkv")
 
-	cfgSrv := newDanmakuSourceServer(t) // /api/v2/comment/25484 → 弹幕A
-	official := danmakuOfficialServer(t,
-		`{"success":true,"isMatched":true,"matches":[{"episodeId":25484,"animeId":1001,"animeTitle":"测试动画"}]}`,
-		`<?xml version="1.0"?><i><d p="0.5,1,16777215,user1">弹幕B官方</d></i>`,
-		nil)
+	// 配置源使用自己的 ID 空间：官方是 90001，配置源是 25484。
+	// 副标题一致，用于跨源确认是同一集。
+	const subtitle = "测试副标题"
+	cfgMux := http.NewServeMux()
+	cfgMux.HandleFunc("/api/v2/search/episodes", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"hasMore":false,"animes":[{"animeId":1001,"animeTitle":"测试动画","episodes":[{"episodeId":25484,"episodeTitle":"第1话 `+subtitle+`"}]}]}`)
+	})
+	cfgMux.HandleFunc("/api/v2/comment/25484", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/xml")
+		fmt.Fprint(w, `<?xml version="1.0"?><i><d p="0.5,1,16777215,user1">弹幕A</d></i>`)
+	})
+	cfgSrv := httptest.NewServer(cfgMux)
+	t.Cleanup(cfgSrv.Close)
+
+	officialMux := http.NewServeMux()
+	officialMux.HandleFunc("/api/v2/match", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"success":true,"isMatched":true,"matches":[{"episodeId":90001,"animeId":1001,"animeTitle":"测试动画","episodeTitle":"第1话 `+subtitle+`"}]}`)
+	})
+	officialMux.HandleFunc("/api/v2/comment/90001", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/xml")
+		fmt.Fprint(w, `<?xml version="1.0"?><i><d p="0.5,1,16777215,user1">弹幕B官方</d></i>`)
+	})
+	official := httptest.NewServer(officialMux)
+	t.Cleanup(official.Close)
 	overrideDanmakuOfficialBase(t, official.URL)
 
 	svc := newDanmakuTestService(t)
 	ctx := context.Background()
-	require.NoError(t, svc.repo.Setting.Set(ctx, DanmakuSourceKey, cfgSrv.URL()))
+	require.NoError(t, svc.repo.Setting.Set(ctx, DanmakuSourceKey, cfgSrv.URL))
 	seedDanmakuVideoMedia(t, svc, "mC", "测试动画", videoPath, 32000, 0)
 
 	res, err := svc.Fetch(ctx, "mC", "", "")
 	require.NoError(t, err)
-	// 配置源优先：弹幕来自自定义源而非官方。
+	// 弹幕取自配置源，且用的是重定位后的 ID。
 	require.Contains(t, res.Raw, "弹幕A")
 	require.NotContains(t, res.Raw, "弹幕B官方")
+	require.Equal(t, int64(25484), res.EpisodeID)
+	require.Equal(t, "hash", res.MatchMode)
+}
+
+// 配置源能定位到该集，但返回的是空弹幕库（count=0）时必须回官方兜底：
+// 第三方目录里有条目不代表真的收录了弹幕。
+func TestDanmakuFetchHashMatchFallsBackWhenConfiguredLibraryIsEmpty(t *testing.T) {
+	videoPath, _ := writeDanmakuTestVideo(t, "测试动画.第01话.mkv")
+
+	const subtitle = "测试副标题"
+	cfgMux := http.NewServeMux()
+	cfgMux.HandleFunc("/api/v2/search/episodes", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"hasMore":false,"animes":[{"animeId":1001,"animeTitle":"测试动画","episodes":[{"episodeId":25484,"episodeTitle":"第1话 `+subtitle+`"}]}]}`)
+	})
+	// 该集在配置源上存在，但弹幕为空。
+	cfgMux.HandleFunc("/api/v2/comment/25484", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"count":0,"comments":[]}`)
+	})
+	cfgSrv := httptest.NewServer(cfgMux)
+	t.Cleanup(cfgSrv.Close)
+
+	officialMux := http.NewServeMux()
+	officialMux.HandleFunc("/api/v2/match", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"success":true,"isMatched":true,"matches":[{"episodeId":90001,"animeId":1001,"animeTitle":"测试动画","episodeTitle":"第1话 `+subtitle+`"}]}`)
+	})
+	officialMux.HandleFunc("/api/v2/comment/90001", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/xml")
+		fmt.Fprint(w, `<?xml version="1.0"?><i><d p="0.5,1,16777215,user1">官方兜底弹幕</d></i>`)
+	})
+	official := httptest.NewServer(officialMux)
+	t.Cleanup(official.Close)
+	overrideDanmakuOfficialBase(t, official.URL)
+
+	svc := newDanmakuTestService(t)
+	ctx := context.Background()
+	require.NoError(t, svc.repo.Setting.Set(ctx, DanmakuSourceKey, cfgSrv.URL))
+	seedDanmakuVideoMedia(t, svc, "mEmpty", "测试动画", videoPath, 32000, 0)
+
+	res, err := svc.Fetch(ctx, "mEmpty", "", "")
+	require.NoError(t, err)
+	require.Contains(t, res.Raw, "官方兜底弹幕")
+	require.Equal(t, int64(90001), res.EpisodeID)
+}
+
+// 同一集在配置源里命中多个来源时：自动加载第一条，其余作为可切换来源返回，
+// 让用户能在面板里直接切换，而不必重新搜索。
+func TestDanmakuFetchHashMatchReturnsAlternatives(t *testing.T) {
+	videoPath, _ := writeDanmakuTestVideo(t, "多来源动画.第01话.mkv")
+
+	const subtitle = "同一个副标题"
+	cfgMux := http.NewServeMux()
+	cfgMux.HandleFunc("/api/v2/search/episodes", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		// 三个来源都指向同一集（副标题与集数一致），模拟 LogVar 聚合多站。
+		fmt.Fprint(w, `{"hasMore":false,"animes":[`+
+			`{"animeId":1,"animeTitle":"多来源动画 from dandan","episodes":[{"episodeId":101,"episodeTitle":"第1话 `+subtitle+`"}]},`+
+			`{"animeId":2,"animeTitle":"多来源动画 from bilibili","episodes":[{"episodeId":102,"episodeTitle":"第1话 `+subtitle+`"}]},`+
+			`{"animeId":3,"animeTitle":"多来源动画 from qq","episodes":[{"episodeId":103,"episodeTitle":"第1话 `+subtitle+`"}]}]}`)
+	})
+	cfgMux.HandleFunc("/api/v2/comment/101", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/xml")
+		fmt.Fprint(w, `<?xml version="1.0"?><i><d p="0.5,1,16777215,user1">首选来源弹幕</d></i>`)
+	})
+	cfgSrv := httptest.NewServer(cfgMux)
+	t.Cleanup(cfgSrv.Close)
+
+	officialMux := http.NewServeMux()
+	officialMux.HandleFunc("/api/v2/match", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"success":true,"isMatched":true,"matches":[{"episodeId":90001,"animeId":9,"animeTitle":"多来源动画","episodeTitle":"第1话 `+subtitle+`"}]}`)
+	})
+	officialMux.HandleFunc("/api/v2/comment/90001", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/xml")
+		fmt.Fprint(w, `<?xml version="1.0"?><i><d p="0.5,1,16777215,user1">官方弹幕</d></i>`)
+	})
+	official := httptest.NewServer(officialMux)
+	t.Cleanup(official.Close)
+	overrideDanmakuOfficialBase(t, official.URL)
+
+	svc := newDanmakuTestService(t)
+	ctx := context.Background()
+	require.NoError(t, svc.repo.Setting.Set(ctx, DanmakuSourceKey, cfgSrv.URL))
+	seedDanmakuVideoMedia(t, svc, "mAlt", "多来源动画", videoPath, 32000, 0)
+
+	res, err := svc.Fetch(ctx, "mAlt", "", "")
+	require.NoError(t, err)
+
+	// 自动加载第一个来源（沿用既有取值逻辑）。
+	require.Contains(t, res.Raw, "首选来源弹幕")
+	require.Equal(t, int64(101), res.EpisodeID)
+	require.Equal(t, "hash", res.MatchMode)
+
+	// 三个来源全部作为可切换列表返回。
+	require.Len(t, res.Alternatives, 3)
+	var ids []int64
+	for _, a := range res.Alternatives {
+		for _, e := range a.Episodes {
+			ids = append(ids, e.EpisodeID)
+		}
+	}
+	require.Equal(t, []int64{101, 102, 103}, ids)
+
+	// Candidates 的语义必须保持不变（这里不是"必须选择"），否则前端会停止自动加载。
+	require.Empty(t, res.Candidates)
+}
+
+// 只有一个来源时不应产生 alternatives，避免面板出现无意义的单条列表。
+func TestDanmakuFetchHashMatchNoAlternativesForSingleSource(t *testing.T) {
+	videoPath, _ := writeDanmakuTestVideo(t, "单来源动画.第01话.mkv")
+
+	const subtitle = "唯一副标题"
+	cfgMux := http.NewServeMux()
+	cfgMux.HandleFunc("/api/v2/search/episodes", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"hasMore":false,"animes":[{"animeId":1,"animeTitle":"单来源动画","episodes":[{"episodeId":201,"episodeTitle":"第1话 `+subtitle+`"}]}]}`)
+	})
+	cfgMux.HandleFunc("/api/v2/comment/201", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/xml")
+		fmt.Fprint(w, `<?xml version="1.0"?><i><d p="0.5,1,16777215,user1">唯一来源弹幕</d></i>`)
+	})
+	cfgSrv := httptest.NewServer(cfgMux)
+	t.Cleanup(cfgSrv.Close)
+
+	officialMux := http.NewServeMux()
+	officialMux.HandleFunc("/api/v2/match", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"success":true,"isMatched":true,"matches":[{"episodeId":90002,"animeId":9,"animeTitle":"单来源动画","episodeTitle":"第1话 `+subtitle+`"}]}`)
+	})
+	official := httptest.NewServer(officialMux)
+	t.Cleanup(official.Close)
+	overrideDanmakuOfficialBase(t, official.URL)
+
+	svc := newDanmakuTestService(t)
+	ctx := context.Background()
+	require.NoError(t, svc.repo.Setting.Set(ctx, DanmakuSourceKey, cfgSrv.URL))
+	seedDanmakuVideoMedia(t, svc, "mOne", "单来源动画", videoPath, 32000, 0)
+
+	res, err := svc.Fetch(ctx, "mOne", "", "")
+	require.NoError(t, err)
+	require.Contains(t, res.Raw, "唯一来源弹幕")
+	require.Empty(t, res.Alternatives)
+}
+
+// 开启合并后：同一集的多个来源被合并，重复弹幕（时间+内容相同）只保留一条。
+func TestDanmakuFetchMergeSourcesCombinesAndDeduplicates(t *testing.T) {
+	videoPath, _ := writeDanmakuTestVideo(t, "合并动画.第01话.mkv")
+
+	const subtitle = "同一副标题"
+	cfgMux := http.NewServeMux()
+	cfgMux.HandleFunc("/api/v2/search/episodes", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"hasMore":false,"animes":[`+
+			`{"animeId":1,"animeTitle":"来源A","episodes":[{"episodeId":301,"episodeTitle":"第1话 `+subtitle+`"}]},`+
+			`{"animeId":2,"animeTitle":"来源B","episodes":[{"episodeId":302,"episodeTitle":"第1话 `+subtitle+`"}]}]}`)
+	})
+	// A 与 B 各有一条重复弹幕（1.0 秒「重复弹幕」）和各自独有的一条。
+	cfgMux.HandleFunc("/api/v2/comment/301", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"count":2,"comments":[`+
+			`{"p":"1.00,1,16777215,u1","m":"重复弹幕"},`+
+			`{"p":"2.00,1,16777215,u1","m":"只在A"}]}`)
+	})
+	cfgMux.HandleFunc("/api/v2/comment/302", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"count":2,"comments":[`+
+			`{"p":"1.00,1,16777215,u2","m":"重复弹幕"},`+
+			`{"p":"3.00,1,16777215,u2","m":"只在B"}]}`)
+	})
+	cfgSrv := httptest.NewServer(cfgMux)
+	t.Cleanup(cfgSrv.Close)
+
+	officialMux := http.NewServeMux()
+	officialMux.HandleFunc("/api/v2/match", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"success":true,"isMatched":true,"matches":[{"episodeId":90003,"animeId":9,"animeTitle":"合并动画","episodeTitle":"第1话 `+subtitle+`"}]}`)
+	})
+	official := httptest.NewServer(officialMux)
+	t.Cleanup(official.Close)
+	overrideDanmakuOfficialBase(t, official.URL)
+
+	svc := newDanmakuTestService(t)
+	ctx := context.Background()
+	require.NoError(t, svc.repo.Setting.Set(ctx, DanmakuSourceKey, cfgSrv.URL))
+	seedDanmakuVideoMedia(t, svc, "mMerge", "合并动画", videoPath, 32000, 0)
+
+	res, err := svc.FetchWithOptions(ctx, "mMerge", "", "", DanmakuFetchOptions{MergeSources: true})
+	require.NoError(t, err)
+	require.Equal(t, 2, res.MergedSources, "expected both sources to be merged")
+
+	merged := parseDanmakuComments(res.Raw)
+	require.Len(t, merged, 3, "duplicate comment must collapse: got %#v", merged)
+	require.Equal(t, "重复弹幕", merged[0].Text)
+	require.Equal(t, 1.0, merged[0].TimeSec)
+	require.Equal(t, "只在A", merged[1].Text)
+	require.Equal(t, "只在B", merged[2].Text)
+	// 合并结果用 JSON 输出，前端据此选择解析分支。
+	require.Equal(t, "json", res.SourceType)
+}
+
+// 未开启合并时，行为与原来一致：只加载自动选中的那一个来源。
+func TestDanmakuFetchWithoutMergeLoadsSingleSource(t *testing.T) {
+	videoPath, _ := writeDanmakuTestVideo(t, "不合并动画.第01话.mkv")
+
+	const subtitle = "同一副标题"
+	cfgMux := http.NewServeMux()
+	cfgMux.HandleFunc("/api/v2/search/episodes", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"hasMore":false,"animes":[`+
+			`{"animeId":1,"animeTitle":"来源A","episodes":[{"episodeId":401,"episodeTitle":"第1话 `+subtitle+`"}]},`+
+			`{"animeId":2,"animeTitle":"来源B","episodes":[{"episodeId":402,"episodeTitle":"第1话 `+subtitle+`"}]}]}`)
+	})
+	cfgMux.HandleFunc("/api/v2/comment/401", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"count":1,"comments":[{"p":"1.00,1,16777215,u1","m":"只在A"}]}`)
+	})
+	cfgMux.HandleFunc("/api/v2/comment/402", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"count":1,"comments":[{"p":"1.00,1,16777215,u2","m":"只在B"}]}`)
+	})
+	cfgSrv := httptest.NewServer(cfgMux)
+	t.Cleanup(cfgSrv.Close)
+
+	officialMux := http.NewServeMux()
+	officialMux.HandleFunc("/api/v2/match", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"success":true,"isMatched":true,"matches":[{"episodeId":90004,"animeId":9,"animeTitle":"不合并动画","episodeTitle":"第1话 `+subtitle+`"}]}`)
+	})
+	official := httptest.NewServer(officialMux)
+	t.Cleanup(official.Close)
+	overrideDanmakuOfficialBase(t, official.URL)
+
+	svc := newDanmakuTestService(t)
+	ctx := context.Background()
+	require.NoError(t, svc.repo.Setting.Set(ctx, DanmakuSourceKey, cfgSrv.URL))
+	seedDanmakuVideoMedia(t, svc, "mNoMerge", "不合并动画", videoPath, 32000, 0)
+
+	res, err := svc.Fetch(ctx, "mNoMerge", "", "")
+	require.NoError(t, err)
+	require.Zero(t, res.MergedSources)
+	require.Equal(t, int64(401), res.EpisodeID)
+	// 只应有自动选中来源的弹幕。
+	require.Contains(t, res.Raw, "只在A")
+	require.NotContains(t, res.Raw, "只在B")
+	// 两个来源仍然作为可切换项返回（合并开关不影响候选列表）。
+	require.Len(t, res.Alternatives, 2)
+}
+
+// 合并偏好按用户持久化。
+func TestDanmakuMergeSourcesPreferencePersistsPerUser(t *testing.T) {
+	svc := newDanmakuTestService(t)
+	ctx := context.Background()
+
+	userA := model.User{Username: "merge-user-a", PasswordHash: "x", Role: "user", IsActive: true}
+	userA.ID = "user-a"
+	userB := model.User{Username: "merge-user-b", PasswordHash: "x", Role: "user", IsActive: true}
+	userB.ID = "user-b"
+	require.NoError(t, svc.repo.User.Create(ctx, &userA))
+	require.NoError(t, svc.repo.User.Create(ctx, &userB))
+
+	require.False(t, svc.MergeSourcesEnabled(ctx, "user-a"))
+	require.NoError(t, svc.SetMergeSources(ctx, "user-a", true))
+	require.True(t, svc.MergeSourcesEnabled(ctx, "user-a"))
+	// 另一个用户不受影响。
+	require.False(t, svc.MergeSourcesEnabled(ctx, "user-b"))
+
+	// 重新读取确认已落库，且 ConfigForUser 会带出该偏好。
+	cfg := svc.ConfigForUser(ctx, "user-a")
+	require.True(t, cfg.MergeSources)
+	require.False(t, svc.ConfigForUser(ctx, "user-b").MergeSources)
+}
+
+// 配置源搜不到对应剧集时必须回退官方：用官方自身的 episodeId 请求官方，
+// 而不是拿官方 ID 去撞配置源。
+func TestDanmakuFetchHashMatchFallsBackToOfficialWhenConfiguredHasNoMatch(t *testing.T) {
+	videoPath, _ := writeDanmakuTestVideo(t, "冷门动画.第01话.mkv")
+
+	cfgMux := http.NewServeMux()
+	cfgMux.HandleFunc("/api/v2/search/episodes", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"hasMore":false,"animes":[]}`)
+	})
+	cfgSrv := httptest.NewServer(cfgMux)
+	t.Cleanup(cfgSrv.Close)
+
+	officialMux := http.NewServeMux()
+	officialMux.HandleFunc("/api/v2/match", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"success":true,"isMatched":true,"matches":[{"episodeId":90001,"animeId":1001,"animeTitle":"冷门动画","episodeTitle":"第1话 无人知晓"}]}`)
+	})
+	officialMux.HandleFunc("/api/v2/comment/90001", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/xml")
+		fmt.Fprint(w, `<?xml version="1.0"?><i><d p="0.5,1,16777215,user1">弹幕来自官方</d></i>`)
+	})
+	official := httptest.NewServer(officialMux)
+	t.Cleanup(official.Close)
+	overrideDanmakuOfficialBase(t, official.URL)
+
+	svc := newDanmakuTestService(t)
+	ctx := context.Background()
+	require.NoError(t, svc.repo.Setting.Set(ctx, DanmakuSourceKey, cfgSrv.URL))
+	seedDanmakuVideoMedia(t, svc, "mNoMatch", "冷门动画", videoPath, 32000, 0)
+
+	res, err := svc.Fetch(ctx, "mNoMatch", "", "")
+	require.NoError(t, err)
+	require.Contains(t, res.Raw, "弹幕来自官方")
+	require.Equal(t, int64(90001), res.EpisodeID)
 }
 
 func TestDanmakuFetchHashMatchConfiguredFailsFallsBackOfficial(t *testing.T) {
@@ -159,13 +491,14 @@ func TestDanmakuFetchHashMatchConfiguredFailsFallsBackOfficial(t *testing.T) {
 	require.Contains(t, res.Raw, "弹幕官方兜底")
 }
 
-// 第 1 层未命中（matches 为空）→ 第 2 层按文件名+集数搜索。
+// 第 1 层未命中时，即使官方附带模糊候选，也不能把第一条当作精准匹配；
+// 应继续走第 2 层按文件名+集数搜索。
 func TestDanmakuFetchHashMissFallsBackToFileNameSearch(t *testing.T) {
 	videoPath, _ := writeDanmakuTestVideo(t, "测试动画.第01话.mkv")
 
 	cfgSrv := newDanmakuSourceServer(t) // 搜索 + 弹幕A
 	official := danmakuOfficialServer(t,
-		`{"success":true,"isMatched":false,"matches":[]}`,
+		`{"success":true,"isMatched":false,"matches":[{"episodeId":120140001,"animeId":12014,"animeTitle":"91天","episodeTitle":"第1话 杀人之夜"}]}`,
 		`<i></i>`, nil)
 	overrideDanmakuOfficialBase(t, official.URL)
 
@@ -178,8 +511,53 @@ func TestDanmakuFetchHashMissFallsBackToFileNameSearch(t *testing.T) {
 	require.NoError(t, err)
 	require.True(t, res.Enabled)
 	require.Contains(t, res.Raw, "弹幕A")
-	// 第 2 层命中：搜索请求按文件名进行。
-	require.Contains(t, cfgSrv.lastSearch, "anime=")
+	require.Equal(t, "filename", res.MatchMode)
+	require.Equal(t, "测试动画", res.AnimeTitle)
+	// 第 2 层命中：搜索请求按文件名进行，而不是误用官方第一条模糊候选。
+	query, err := url.ParseQuery(cfgSrv.lastSearch)
+	require.NoError(t, err)
+	require.Contains(t, query.Get("anime"), "测试动画.第01话")
+	require.NotContains(t, query.Get("anime"), "91天")
+}
+
+// hash 未精确命中时，若本地已有刮削的剧名、年份、集数和集标题，应先用这些
+// 元数据锁定正确来源，而不是直接进入大量候选的手工选择。
+func TestDanmakuFetchHashMissUsesScrapedMetadata(t *testing.T) {
+	videoPath, _ := writeDanmakuTestVideo(t, "local-release-name.mkv")
+	cfgSrv := newDanmakuSourceServerWithSearch(t,
+		`{"hasMore":false,"animes":[`+
+			`{"animeId":1,"animeTitle":"命运石之门 0(2018)【TV动画】from dandan&animeko","episodes":[{"episodeId":120140001,"episodeTitle":"【dandan&animeko】 第1话 零化域的缺失之环-Absolute Zero-"}]},`+
+			`{"animeId":2,"animeTitle":"命运石之门(2011)【TV动画】from dandan&animeko","episodes":[{"episodeId":25484,"episodeTitle":"【dandan&animeko】 第1话 始与终的序章-Turning Point-"}]},`+
+			`{"animeId":3,"animeTitle":"命运石之门(2011)【动漫】from 360","episodes":[{"episodeId":120140002,"episodeTitle":"【qq】 第1集"}]}`+
+			`]}`)
+	official := danmakuOfficialServer(t,
+		`{"success":true,"isMatched":false,"matches":[{"episodeId":120140001,"animeId":12014,"animeTitle":"91天","episodeTitle":"第1话 杀人之夜"}]}`,
+		`<i></i>`, nil)
+	overrideDanmakuOfficialBase(t, official.URL)
+
+	svc := newDanmakuTestService(t)
+	ctx := context.Background()
+	require.NoError(t, svc.repo.Setting.Set(ctx, DanmakuSourceKey, cfgSrv.URL()))
+	media := model.Media{
+		Title:        "命运石之门",
+		Year:         2011,
+		EpisodeNum:   1,
+		EpisodeTitle: "起始与终结的序章",
+		Path:         videoPath,
+		SizeBytes:    32000,
+		ScrapeStatus: "matched",
+	}
+	media.ID = "mScrapedMeta"
+	require.NoError(t, svc.repo.DB.Create(&media).Error)
+
+	res, err := svc.Fetch(ctx, media.ID, "", "")
+	require.NoError(t, err)
+	require.True(t, res.Enabled)
+	require.Contains(t, res.Raw, "弹幕A")
+	require.Equal(t, "metadata", res.MatchMode)
+	require.Equal(t, "命运石之门(2011)【TV动画】from dandan&animeko", res.AnimeTitle)
+	require.Equal(t, int64(25484), res.EpisodeID)
+	require.Empty(t, res.Candidates)
 }
 
 // strm：通过解析出的直链 Range 拉 16MB 前缀算 hash → match → 拉弹幕。
@@ -446,3 +824,38 @@ func TestDanmakuFetchEmbyRemoteStreamFailedFallsBackToSearch(t *testing.T) {
 	require.Equal(t, "降级搜索番剧", res.AnimeTitle)
 	require.Contains(t, res.Raw, "降级搜索弹幕")
 }
+
+// 即使刮削元数据完整，也应先走准确率最高的 hash 层。
+func TestDanmakuFetchPrefersHashOverCompleteMetadata(t *testing.T) {
+	videoPath, wantHash := writeDanmakuTestVideo(t, "测试动画.第01话.mkv")
+	var seen string
+	official := danmakuOfficialServer(t,
+		`{"success":true,"isMatched":true,"matches":[{"episodeId":25484,"animeId":1001,"animeTitle":"官方测试动画","episodeTitle":"第1话"}]}`,
+		`<?xml version="1.0"?><i><d p="0.5,1,16777215,user1">hash命中</d></i>`,
+		&seen)
+	overrideDanmakuOfficialBase(t, official.URL)
+
+	source := newDanmakuSourceServerWithSearch(t,
+		`{"hasMore":false,"animes":[{"animeId":2002,"animeTitle":"官方测试动画","episodes":[{"episodeId":25484,"episodeTitle":"第1话"}]}]}`)
+
+	svc := newDanmakuTestService(t)
+	ctx := context.Background()
+	require.NoError(t, svc.repo.Setting.Set(ctx, DanmakuSourceKey, source.URL()))
+
+	m := model.Media{
+		Title:        "测试动画",
+		Path:         videoPath,
+		SizeBytes:    123,
+		EpisodeNum:   1,
+		EpisodeTitle: "起始与终结的序章",
+		Year:         2011,
+	}
+	m.ID = "hash-first"
+	require.NoError(t, svc.repo.DB.Create(&m).Error)
+
+	res, err := svc.Fetch(ctx, "hash-first", "", "")
+	require.NoError(t, err)
+	require.Equal(t, "hash", res.MatchMode)
+	require.NotEmpty(t, res.Raw)
+	require.Contains(t, seen, wantHash)
+}

internal/service/danmaku_merge.go

@@ -0,0 +1,220 @@
+package service
+
+import (
+	"encoding/json"
+	"encoding/xml"
+	"fmt"
+	"math"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+// 弹幕合并：同一集在聚合源（如 LogVar）里常有多个库，开启合并后把这些库的
+// 弹幕一起去重后展示，而不是只显示其中一个。
+const (
+	// danmakuMergeMaxSources 限制一次合并涉及的来源数量，避免把一次播放
+	// 变成几十个上游请求。
+	danmakuMergeMaxSources = 10
+	// danmakuMergeConcurrency 限制并发抓取数，降低触发上游限流（429）的概率。
+	danmakuMergeConcurrency = 4
+	// danmakuMergeTimeToleranceSec 是判定「同一时间点」的容差。同一条弹幕在
+	// 不同源之间可能因精度处理差上零点几秒，用容差比对；文本仍要求完全一致，
+	// 因此不会把内容不同的弹幕误合。
+	danmakuMergeTimeToleranceSec = 0.5
+)
+
+// danmakuComment 是合并用的归一化弹幕。
+type danmakuComment struct {
+	TimeSec float64
+	Mode    int
+	Color   int
+	Text    string
+}
+
+// parseDanmakuComments 把上游载荷解析成归一化弹幕列表，兼容 dandanplay
+// JSON（{comments:[{p,m}]}）与 Bilibili XML（<d p="...">text</d>）两种格式。
+// 无法识别的载荷返回空列表，调用方据此跳过该来源。
+func parseDanmakuComments(raw string) []danmakuComment {
+	trimmed := strings.TrimSpace(raw)
+	if trimmed == "" {
+		return nil
+	}
+	if strings.HasPrefix(trimmed, "{") || strings.HasPrefix(trimmed, "[") {
+		if comments := parseDanmakuCommentsJSON(trimmed); len(comments) > 0 {
+			return comments
+		}
+	}
+	if strings.HasPrefix(trimmed, "<") {
+		return parseDanmakuCommentsXML(trimmed)
+	}
+	return nil
+}
+
+func parseDanmakuCommentsJSON(raw string) []danmakuComment {
+	// 兼容 {comments:[...]} 与裸数组两种形态。
+	var payload struct {
+		Comments []struct {
+			P string `json:"p"`
+			M string `json:"m"`
+			// 少数自建源直接给结构化字段。
+			Time  *float64 `json:"time"`
+			Text  string   `json:"text"`
+			Mode  *int     `json:"mode"`
+			Color *int     `json:"color"`
+		} `json:"comments"`
+	}
+	if err := json.Unmarshal([]byte(raw), &payload); err != nil {
+		var bare []struct {
+			P     string   `json:"p"`
+			M     string   `json:"m"`
+			Time  *float64 `json:"time"`
+			Text  string   `json:"text"`
+			Mode  *int     `json:"mode"`
+			Color *int     `json:"color"`
+		}
+		if err2 := json.Unmarshal([]byte(raw), &bare); err2 != nil {
+			return nil
+		}
+		payload.Comments = bare
+	}
+	out := make([]danmakuComment, 0, len(payload.Comments))
+	for _, item := range payload.Comments {
+		comment, ok := buildDanmakuComment(item.P, item.M, item.Time, item.Text, item.Mode, item.Color)
+		if ok {
+			out = append(out, comment)
+		}
+	}
+	return out
+}
+
+func parseDanmakuCommentsXML(raw string) []danmakuComment {
+	var doc struct {
+		Items []struct {
+			P    string `xml:"p,attr"`
+			Text string `xml:",chardata"`
+		} `xml:"d"`
+	}
+	if err := xml.Unmarshal([]byte(raw), &doc); err != nil {
+		return nil
+	}
+	out := make([]danmakuComment, 0, len(doc.Items))
+	for _, item := range doc.Items {
+		comment, ok := buildDanmakuComment(item.P, item.Text, nil, "", nil, nil)
+		if ok {
+			out = append(out, comment)
+		}
+	}
+	return out
+}
+
+// buildDanmakuComment 从 p 串或结构化字段构造一条弹幕。p 串格式为
+// "time,mode,color,user"（dandanplay 四段式）。
+func buildDanmakuComment(p, text string, timeSec *float64, plainText string, mode, color *int) (danmakuComment, bool) {
+	body := strings.TrimSpace(text)
+	if body == "" {
+		body = strings.TrimSpace(plainText)
+	}
+	if body == "" {
+		return danmakuComment{}, false
+	}
+	comment := danmakuComment{Text: body, Mode: 1}
+	if timeSec != nil {
+		comment.TimeSec = *timeSec
+	}
+	if mode != nil && *mode > 0 {
+		comment.Mode = *mode
+	}
+	if color != nil {
+		comment.Color = *color
+	}
+	if fields := strings.Split(p, ","); len(fields) >= 1 {
+		if t, err := strconv.ParseFloat(strings.TrimSpace(fields[0]), 64); err == nil {
+			comment.TimeSec = t
+		}
+		if len(fields) >= 2 {
+			if m, err := strconv.Atoi(strings.TrimSpace(fields[1])); err == nil && m > 0 {
+				comment.Mode = m
+			}
+		}
+		// 颜色所在位置取决于格式，用段数区分（与前端 parseBilibiliXml 的判定
+		// 一致）：Bilibili 的 p 是 "time,mode,fontSize,color,..."（>=5 段，
+		// 颜色在第 4 段）；dandanplay 的 p 是 "time,mode,color,userId"（4 段，
+		// 颜色在第 3 段）。不区分会把字号当成颜色。
+		colorIndex := 2
+		if len(fields) >= 5 {
+			colorIndex = 3
+		}
+		if len(fields) > colorIndex {
+			if c, err := strconv.Atoi(strings.TrimSpace(fields[colorIndex])); err == nil {
+				comment.Color = c
+			}
+		}
+	}
+	if math.IsNaN(comment.TimeSec) || math.IsInf(comment.TimeSec, 0) || comment.TimeSec < 0 {
+		return danmakuComment{}, false
+	}
+	// 无颜色信息时用白色，与前端默认一致。
+	if comment.Color <= 0 {
+		comment.Color = 16777215
+	}
+	return comment, true
+}
+
+// mergeDanmakuComments 合并多组弹幕并按「时间 + 内容」去重。
+//
+// 判定重复的条件：文本完全一致，且时间差在 danmakuMergeTimeToleranceSec 以内。
+// 之所以同时要求文本一致，是因为容差本身不足以区分内容；之所以需要容差，
+// 是因为同一条弹幕在不同来源间可能因精度处理差上零点几秒。
+func mergeDanmakuComments(sets [][]danmakuComment) []danmakuComment {
+	merged := make([]danmakuComment, 0, 512)
+	// keptTimes[文本] = 已保留的该文本时间列表，用于就近比对。
+	keptTimes := make(map[string][]float64)
+	for _, set := range sets {
+		for _, comment := range set {
+			times := keptTimes[comment.Text]
+			duplicate := false
+			for _, kept := range times {
+				if math.Abs(kept-comment.TimeSec) <= danmakuMergeTimeToleranceSec {
+					duplicate = true
+					break
+				}
+			}
+			if duplicate {
+				continue
+			}
+			keptTimes[comment.Text] = append(times, comment.TimeSec)
+			merged = append(merged, comment)
+		}
+	}
+	sort.SliceStable(merged, func(i, j int) bool { return merged[i].TimeSec < merged[j].TimeSec })
+	return merged
+}
+
+// encodeDanmakuComments 把合并结果编码成 dandanplay JSON，前端 parseDanmaku
+// 已支持该格式（{comments:[{p,m}]}）。
+func encodeDanmakuComments(comments []danmakuComment) string {
+	type item struct {
+		Cid int    `json:"cid"`
+		P   string `json:"p"`
+		M   string `json:"m"`
+		T   int    `json:"t"`
+	}
+	payload := struct {
+		Count    int    `json:"count"`
+		Comments []item `json:"comments"`
+	}{Count: len(comments), Comments: make([]item, 0, len(comments))}
+	for i, comment := range comments {
+		payload.Comments = append(payload.Comments, item{
+			Cid: i + 1,
+			P:   fmt.Sprintf("%.2f,%d,%d,merged", comment.TimeSec, comment.Mode, comment.Color),
+			M:   comment.Text,
+			T:   int(comment.TimeSec),
+		})
+	}
+	encoded, err := json.Marshal(payload)
+	if err != nil {
+		return ""
+	}
+	return string(encoded)
+}

internal/service/danmaku_merge_test.go

@@ -0,0 +1,125 @@
+package service
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseDanmakuCommentsSupportsDandanplayJson(t *testing.T) {
+	raw := `{"count":2,"comments":[` +
+		`{"cid":1,"p":"1.50,1,16777215,userA","m":"第一条"},` +
+		`{"cid":2,"p":"2.00,5,16711680,userB","m":"顶部红字"}]}`
+	comments := parseDanmakuComments(raw)
+	require.Len(t, comments, 2)
+	require.Equal(t, 1.5, comments[0].TimeSec)
+	require.Equal(t, 1, comments[0].Mode)
+	require.Equal(t, 16777215, comments[0].Color)
+	require.Equal(t, "第一条", comments[0].Text)
+	// 第 5 种模式是顶部弹幕，颜色 16711680 = 0xFF0000。
+	require.Equal(t, 5, comments[1].Mode)
+	require.Equal(t, 16711680, comments[1].Color)
+}
+
+func TestParseDanmakuCommentsSupportsBilibiliXml(t *testing.T) {
+	raw := `<?xml version="1.0" encoding="UTF-8"?><i>` +
+		`<d p="3.25,1,25,16777215,1700000000,0,abc,def">来自 XML</d>` +
+		`</i>`
+	comments := parseDanmakuComments(raw)
+	require.Len(t, comments, 1)
+	require.Equal(t, 3.25, comments[0].TimeSec)
+	require.Equal(t, "来自 XML", comments[0].Text)
+	// Bilibili 的 5 段式里第 3 段是字号、第 4 段才是颜色，必须取第 4 段。
+	require.Equal(t, 16777215, comments[0].Color)
+}
+
+func TestParseDanmakuCommentsReturnsNilForUnsupportedPayload(t *testing.T) {
+	require.Nil(t, parseDanmakuComments(""))
+	require.Nil(t, parseDanmakuComments("not a danmaku payload"))
+}
+
+// 同一时间 + 同一内容视为重复，只保留一条。
+func TestMergeDanmakuCommentsDeduplicatesByTimeAndText(t *testing.T) {
+	setA := []danmakuComment{
+		{TimeSec: 1.0, Mode: 1, Color: 16777215, Text: "哈哈"},
+		{TimeSec: 5.0, Mode: 1, Color: 16777215, Text: "只有A有"},
+	}
+	setB := []danmakuComment{
+		{TimeSec: 1.0, Mode: 1, Color: 16777215, Text: "哈哈"}, // 与 A 完全重复
+		{TimeSec: 5.2, Mode: 1, Color: 16777215, Text: "只有B有"},
+	}
+	merged := mergeDanmakuComments([][]danmakuComment{setA, setB})
+	require.Len(t, merged, 3)
+	require.Equal(t, 1.0, merged[0].TimeSec)
+	require.Equal(t, "哈哈", merged[0].Text)
+	require.Equal(t, "只有A有", merged[1].Text)
+	require.Equal(t, "只有B有", merged[2].Text)
+}
+
+// 时间差在容差内且文本一致时也判为重复（跨源可能有零点几秒的精度差）。
+func TestMergeDanmakuCommentsDeduplicatesWithinTolerance(t *testing.T) {
+	merged := mergeDanmakuComments([][]danmakuComment{
+		{{TimeSec: 10.0, Mode: 1, Text: "2333"}},
+		{{TimeSec: 10.3, Mode: 1, Text: "2333"}},
+	})
+	require.Len(t, merged, 1)
+	require.Equal(t, 10.0, merged[0].TimeSec)
+}
+
+// 内容相同但时间相距较远时是两条独立弹幕，不能合并。
+func TestMergeDanmakuCommentsKeepsSameTextAtDifferentTimes(t *testing.T) {
+	merged := mergeDanmakuComments([][]danmakuComment{
+		{{TimeSec: 1.0, Mode: 1, Text: "前方高能"}},
+		{{TimeSec: 30.0, Mode: 1, Text: "前方高能"}},
+	})
+	require.Len(t, merged, 2)
+}
+
+// 时间相同但内容不同也不能合并。
+func TestMergeDanmakuCommentsKeepsDifferentTextAtSameTime(t *testing.T) {
+	merged := mergeDanmakuComments([][]danmakuComment{
+		{{TimeSec: 2.0, Mode: 1, Text: "AAA"}},
+		{{TimeSec: 2.0, Mode: 1, Text: "BBB"}},
+	})
+	require.Len(t, merged, 2)
+}
+
+func TestMergeDanmakuCommentsSortsByTime(t *testing.T) {
+	merged := mergeDanmakuComments([][]danmakuComment{
+		{{TimeSec: 9.0, Mode: 1, Text: "后"}},
+		{{TimeSec: 1.0, Mode: 1, Text: "前"}},
+	})
+	require.Len(t, merged, 2)
+	require.Equal(t, 1.0, merged[0].TimeSec)
+	require.Equal(t, 9.0, merged[1].TimeSec)
+}
+
+// 编码结果必须能被前端的 dandanplay JSON 分支解析（p + m 两个字符串字段）。
+func TestEncodeDanmakuCommentsProducesDandanplayShape(t *testing.T) {
+	encoded := encodeDanmakuComments([]danmakuComment{
+		{TimeSec: 1.5, Mode: 5, Color: 16711680, Text: "顶部"},
+	})
+	var payload struct {
+		Count    int `json:"count"`
+		Comments []struct {
+			Cid int    `json:"cid"`
+			P   string `json:"p"`
+			M   string `json:"m"`
+			T   int    `json:"t"`
+		} `json:"comments"`
+	}
+	require.NoError(t, json.Unmarshal([]byte(encoded), &payload))
+	require.Equal(t, 1, payload.Count)
+	require.Len(t, payload.Comments, 1)
+	require.Equal(t, "1.50,5,16711680,merged", payload.Comments[0].P)
+	require.Equal(t, "顶部", payload.Comments[0].M)
+
+	// 回环：编码后的载荷应能再次解析出一致的弹幕。
+	roundTrip := parseDanmakuComments(encoded)
+	require.Len(t, roundTrip, 1)
+	require.Equal(t, 1.5, roundTrip[0].TimeSec)
+	require.Equal(t, 5, roundTrip[0].Mode)
+	require.Equal(t, 16711680, roundTrip[0].Color)
+	require.Equal(t, "顶部", roundTrip[0].Text)
+}

internal/service/danmaku_service.go

@@ -13,10 +13,14 @@ import (
 	"net/url"
 	"os"
 	"path/filepath"
+	"regexp"
 	"strconv"
 	"strings"
 	"sync"
 	"time"
+	"unicode"
+
+	"golang.org/x/sync/singleflight"
 
 	"go.uber.org/zap"
 
@@ -57,6 +61,14 @@ type DanmakuRenderConfig struct {
 	Opacity  string `json:"opacity"`
 	FontSize string `json:"font_size"`
 	Area     string `json:"area"`
+	// MergeSources 是当前用户的弹幕合并偏好（按用户存储）。
+	MergeSources bool `json:"merge_sources"`
+}
+
+// DanmakuFetchOptions 承载单次抓取的调用方偏好。
+type DanmakuFetchOptions struct {
+	// MergeSources 为真时，同一集的多个来源会被合并去重后一起返回。
+	MergeSources bool
 }
 
 // DanmakuFetchResult is what /api/danmaku/:id returns. Raw holds the upstream
@@ -71,13 +83,21 @@ type DanmakuRenderConfig struct {
 // metadata so the player UI can display which episode was loaded.
 type DanmakuFetchResult struct {
 	DanmakuRenderConfig
-	SourceType   string         `json:"source_type"`
-	Raw          string         `json:"raw,omitempty"`
-	Candidates   []DanmakuAnime `json:"candidates,omitempty"`
+	SourceType string         `json:"source_type"`
+	Raw        string         `json:"raw,omitempty"`
+	Candidates []DanmakuAnime `json:"candidates,omitempty"`
+	// Alternatives 是「同一集的其它可选来源」。与 Candidates 语义不同：
+	// Candidates 表示自动匹配不唯一、必须由用户选择后才能加载弹幕；
+	// Alternatives 表示弹幕已经自动加载好了，这里额外提供同集的其它来源
+	// （LogVar 聚合了多个视频网站，同一集常有多个库）供用户随时切换，
+	// 不必再手动搜索一遍。
+	Alternatives []DanmakuAnime `json:"alternatives,omitempty"`
 	AnimeTitle   string         `json:"anime_title,omitempty"`
 	EpisodeTitle string         `json:"episode_title,omitempty"`
 	EpisodeID    int64          `json:"episode_id,omitempty"`
 	MatchMode    string         `json:"match_mode,omitempty"`
+	// MergedSources 表示本次结果由多少个来源合并而成（未合并时为 0）。
+	MergedSources int `json:"merged_sources,omitempty"`
 }
 
 // DanmakuAnime is one search hit (an anime) with its episode list, mirroring
@@ -118,6 +138,12 @@ type DanmakuService struct {
 
 	hashCacheMu sync.Mutex
 	hashCache   map[string]string // stamp → 16MB-prefix MD5
+
+	// resultCache 缓存整条弹幕抓取结果，避免同一集重复播放时重走
+	// 「16MB 哈希 + 上游搜索 + 评论拉取」这条高延迟链路。
+	resultCacheMu sync.Mutex
+	resultCache   map[string]danmakuResultCacheEntry
+	fetchGroup    singleflight.Group
 }
 
 func danmakuHTTPClient() *http.Client {
@@ -129,10 +155,11 @@ func NewDanmakuService(log *zap.Logger, repo *repository.Container) *DanmakuServ
 		log = zap.NewNop()
 	}
 	return &DanmakuService{
-		log:       log,
-		repo:      repo,
-		client:    danmakuHTTPClient(),
-		hashCache: make(map[string]string),
+		log:         log,
+		repo:        repo,
+		client:      danmakuHTTPClient(),
+		hashCache:   make(map[string]string),
+		resultCache: make(map[string]danmakuResultCacheEntry),
 	}
 }
 
@@ -152,6 +179,121 @@ func (s *DanmakuService) SetRemoteMediaResolver(resolve DanmakuRemoteMediaResolv
 	}
 }
 
+// 弹幕抓取结果缓存：同一集在 TTL 内重复播放时直接返回，避免重复执行
+// 「16MB 前置哈希 → 上游搜索 → 评论拉取」这条高延迟链路。弹幕库内容变化
+// 很慢，而用户通常会在短时间内反复切集/回看，因此 TTL 取 6 小时。
+const (
+	danmakuResultCacheTTL        = 6 * time.Hour
+	danmakuResultCacheMaxEntries = 64
+	// 候选列表由上游搜索决定，相对稳定但可能随源更新，缓存 10 分钟。
+	danmakuResultCacheCandidateTTL = 10 * time.Minute
+	// 空结果可能只是上游临时抖动，只短暂缓存，避免长时间看不到弹幕。
+	danmakuResultCacheEmptyTTL = time.Minute
+)
+
+type danmakuResultCacheEntry struct {
+	result    *DanmakuFetchResult
+	expiresAt time.Time
+	storedAt  time.Time
+}
+
+func danmakuResultCacheKey(source, mediaID, keyword, episodeID string, merge bool) string {
+	return strings.Join([]string{
+		strings.TrimSpace(source),
+		mediaID,
+		strings.TrimSpace(keyword),
+		strings.TrimSpace(episodeID),
+		strconv.FormatBool(merge),
+	}, "\x00")
+}
+
+func (s *DanmakuService) resultCacheGet(key string) (*DanmakuFetchResult, bool) {
+	if s == nil || key == "" {
+		return nil, false
+	}
+	now := time.Now()
+	s.resultCacheMu.Lock()
+	defer s.resultCacheMu.Unlock()
+	entry, ok := s.resultCache[key]
+	if !ok {
+		return nil, false
+	}
+	if now.After(entry.expiresAt) {
+		delete(s.resultCache, key)
+		return nil, false
+	}
+	return cloneDanmakuFetchResult(entry.result), true
+}
+
+func (s *DanmakuService) resultCachePut(key string, result *DanmakuFetchResult) {
+	if s == nil || key == "" || result == nil {
+		return
+	}
+	now := time.Now()
+	s.resultCacheMu.Lock()
+	defer s.resultCacheMu.Unlock()
+	if s.resultCache == nil {
+		s.resultCache = make(map[string]danmakuResultCacheEntry)
+	}
+	ttl := danmakuResultCacheTTLFor(result)
+	if ttl <= 0 {
+		return
+	}
+	if _, exists := s.resultCache[key]; !exists && len(s.resultCache) >= danmakuResultCacheMaxEntries {
+		oldestKey := ""
+		var oldest time.Time
+		for k, entry := range s.resultCache {
+			if oldestKey == "" || entry.storedAt.Before(oldest) {
+				oldestKey, oldest = k, entry.storedAt
+			}
+		}
+		delete(s.resultCache, oldestKey)
+	}
+	s.resultCache[key] = danmakuResultCacheEntry{
+		result:    cloneDanmakuFetchResult(result),
+		expiresAt: now.Add(ttl),
+		storedAt:  now,
+	}
+}
+
+// danmakuResultCacheTTLFor 按结果完整性选择缓存时长：拿到弹幕正文才值得
+// 长缓存；只有候选列表时短缓存；空结果只缓存一分钟。
+func danmakuResultCacheTTLFor(result *DanmakuFetchResult) time.Duration {
+	if result == nil {
+		return 0
+	}
+	if strings.TrimSpace(result.Raw) != "" {
+		return danmakuResultCacheTTL
+	}
+	if len(result.Candidates) > 0 {
+		return danmakuResultCacheCandidateTTL
+	}
+	return danmakuResultCacheEmptyTTL
+}
+
+// cloneDanmakuFetchResult 深拷贝切片字段，避免缓存命中后调用方修改共享数据。
+func cloneDanmakuFetchResult(in *DanmakuFetchResult) *DanmakuFetchResult {
+	if in == nil {
+		return nil
+	}
+	out := *in
+	out.Candidates = cloneDanmakuAnimeList(in.Candidates)
+	out.Alternatives = cloneDanmakuAnimeList(in.Alternatives)
+	return &out
+}
+
+func cloneDanmakuAnimeList(in []DanmakuAnime) []DanmakuAnime {
+	if in == nil {
+		return nil
+	}
+	out := make([]DanmakuAnime, len(in))
+	for i, anime := range in {
+		out[i] = anime
+		out[i].Episodes = append([]DanmakuEpisode(nil), anime.Episodes...)
+	}
+	return out
+}
+
 // Config reads danmaku settings from the runtime settings table.
 func (s *DanmakuService) Config(ctx context.Context) DanmakuRenderConfig {
 	cfg := DanmakuRenderConfig{
@@ -177,6 +319,41 @@ func (s *DanmakuService) Config(ctx context.Context) DanmakuRenderConfig {
 	return cfg
 }
 
+// ConfigForUser 在全局渲染设置之外附加当前用户的个性化偏好。
+func (s *DanmakuService) ConfigForUser(ctx context.Context, userID string) DanmakuRenderConfig {
+	cfg := s.Config(ctx)
+	cfg.MergeSources = s.MergeSourcesEnabled(ctx, userID)
+	return cfg
+}
+
+// MergeSourcesEnabled 返回该用户的弹幕合并偏好，读取失败时回退为关闭。
+func (s *DanmakuService) MergeSourcesEnabled(ctx context.Context, userID string) bool {
+	if s == nil || s.repo == nil || s.repo.User == nil {
+		return false
+	}
+	userID = strings.TrimSpace(userID)
+	if userID == "" {
+		return false
+	}
+	user, err := s.repo.User.FindByID(ctx, userID)
+	if err != nil || user == nil {
+		return false
+	}
+	return user.DanmakuMergeSources
+}
+
+// SetMergeSources 持久化该用户的弹幕合并偏好。
+func (s *DanmakuService) SetMergeSources(ctx context.Context, userID string, enabled bool) error {
+	if s == nil || s.repo == nil || s.repo.User == nil {
+		return errors.New("danmaku settings unavailable")
+	}
+	userID = strings.TrimSpace(userID)
+	if userID == "" {
+		return errors.New("missing user")
+	}
+	return s.repo.User.UpdateFields(ctx, userID, map[string]any{"danmaku_merge_sources": enabled})
+}
+
 // Fetch retrieves danmaku for the given media. keyword overrides the
 // media-derived search term (empty = use the video's own name); pass it from
 // the player when the user searches for a custom title. episodeID forces a
@@ -186,19 +363,60 @@ func (s *DanmakuService) Config(ctx context.Context) DanmakuRenderConfig {
 //  1. match: MD5 of the first 16MB of the video (local file read directly,
 //     .strm resolved to a direct link and range-fetched) → /api/v2/match
 //     against the official endpoint, which yields the episode library id.
-//  2. search by the playing file's name + episode number.
-//  3. current auto-identification (original name → title → file name + episode,
+//  2. scraped metadata: title + episode number + episode title, filtered by
+//     release year and subtitle to disambiguate same-name seasons.
+//  3. search by the playing file's name + episode number.
+//  4. current auto-identification (original name → title → file name + episode,
 //     single hit used, several hits returned as candidates for the player).
-//  4. manual: the player picks from the returned candidates (episodeID /
+//  5. manual: the player picks from the returned candidates (episodeID /
 //     keyword override).
 //
 // Comments are always fetched from the configured source first (when set)
-// and fall back to the official endpoint on failure; identification itself
+// and fall back to the official endpoint on failure. Only hash identification
 // always goes to the official endpoint.
 //
 // When danmaku is disabled the result carries Enabled=false so the player can
 // silently skip rendering.
 func (s *DanmakuService) Fetch(ctx context.Context, mediaID, keyword, episodeID string) (*DanmakuFetchResult, error) {
+	return s.FetchWithOptions(ctx, mediaID, keyword, episodeID, DanmakuFetchOptions{})
+}
+
+// FetchWithOptions 是 Fetch 的带偏好版本。结果按「配置源 + 媒体 + 关键词 +
+// 指定集 + 合并开关」缓存，并用 singleflight 合并并发请求，避免同一集被重复抓取。
+func (s *DanmakuService) FetchWithOptions(ctx context.Context, mediaID, keyword, episodeID string, opts DanmakuFetchOptions) (*DanmakuFetchResult, error) {
+	if s == nil {
+		return nil, errors.New("danmaku service unavailable")
+	}
+	cfg := s.Config(ctx)
+	if !cfg.Enabled {
+		return &DanmakuFetchResult{DanmakuRenderConfig: cfg, SourceType: "auto"}, nil
+	}
+	key := danmakuResultCacheKey(cfg.Source, mediaID, keyword, episodeID, opts.MergeSources)
+	if cached, ok := s.resultCacheGet(key); ok {
+		return cached, nil
+	}
+	value, err, _ := s.fetchGroup.Do(key, func() (any, error) {
+		// 等待期间可能已有同一 key 的请求写入缓存。
+		if cached, ok := s.resultCacheGet(key); ok {
+			return cached, nil
+		}
+		res, err := s.fetchWithOptionsUncached(ctx, mediaID, keyword, episodeID, opts)
+		if err != nil {
+			// 与原实现一致：失败时仍把已填充的渲染配置/匹配信息交给调用方。
+			return res, err
+		}
+		s.resultCachePut(key, res)
+		return res, nil
+	})
+	res, _ := value.(*DanmakuFetchResult)
+	if err != nil {
+		return cloneDanmakuFetchResult(res), err
+	}
+	return cloneDanmakuFetchResult(res), nil
+}
+
+// fetchWithOptionsUncached 是未命中缓存时执行的原始抓取流程。
+func (s *DanmakuService) fetchWithOptionsUncached(ctx context.Context, mediaID, keyword, episodeID string, opts DanmakuFetchOptions) (*DanmakuFetchResult, error) {
 	res := &DanmakuFetchResult{DanmakuRenderConfig: s.Config(ctx), SourceType: "auto"}
 	if !res.Enabled {
 		return res, nil
@@ -234,6 +452,12 @@ func (s *DanmakuService) Fetch(ctx context.Context, mediaID, keyword, episodeID
 	}
 
 	target := ""
+	// targetBase 是 target 所属的源。各源的 episodeId 空间互相独立，必须用
+	// 产生该 ID 的源去请求弹幕，否则会拿到 404；默认沿用「配置源优先」行为。
+	targetBase := configured
+	// hashOfficialID 记录 hash 层的官方 episodeId。仅当配置源重定位成功时
+	// 才填，用于「配置源该集无弹幕」时回官方兜底。
+	hashOfficialID := int64(0)
 
 	// 1) hash 识别：始终走官方 /api/v2/match（keyword 手动覆盖时跳过，直接走第 3 层）。
 	if target == "" && !manualKeyword && media != nil && (media.Path != "" || IsEmbyRemoteID(media.ID)) {
@@ -250,21 +474,59 @@ func (s *DanmakuService) Fetch(ctx context.Context, mediaID, keyword, episodeID
 			if err != nil {
 				s.log.Warn("danmaku hash match failed", zap.String("media_id", mediaID), zap.Error(err))
 			} else if len(matches) > 0 {
-				target = fmt.Sprintf("%d", matches[0].EpisodeID)
-				res.AnimeTitle = matches[0].AnimeTitle
-				res.EpisodeTitle = matches[0].EpisodeTitle
-				res.EpisodeID = matches[0].EpisodeID
+				match := matches[0]
+				res.AnimeTitle = match.AnimeTitle
+				res.EpisodeTitle = match.EpisodeTitle
+				res.EpisodeID = match.EpisodeID
 				res.MatchMode = "hash"
+				// match 返回的是官方 ID 空间的 episodeId，直接拿去问第三方源
+				// 只会 404（实测各源 ID 空间独立）。先用官方给到的剧名+集数
+				// 在配置源里重定位到它自己的 episodeId；定位不到就整条走官方。
+				if configured != "" && !sameDanmakuBase(configured, official) {
+					if matched, ok := s.lookupConfiguredEpisodes(ctx, configured, match); ok {
+						configuredID := firstDanmakuEpisodeID(matched)
+						target = strconv.FormatInt(configuredID, 10)
+						targetBase = configured
+						res.EpisodeID = configuredID
+						hashOfficialID = match.EpisodeID
+						// 同集有多个来源时全部带上，供面板里直接切换。
+						if len(matched) > 1 {
+							res.Alternatives = matched
+						}
+					}
+				}
+				if target == "" {
+					target = strconv.FormatInt(match.EpisodeID, 10)
+					targetBase = official
+				}
 			}
 		}
 	}
 
-	// 2) 按播放的文件名 + 集数搜索（keyword 手动覆盖时跳过，直接走第 3 层）。
+	// 2) hash 未命中时，优先使用刮削后的剧名、集数和集标题匹配。
+	// 该层能解决官方 hash 库未收录、但本地已经刮削出准确季度和单集标题的情况。
+	if target == "" && !manualKeyword && media != nil {
+		if matched, base, ok := s.lookupScrapedEpisodes(ctx, configured, official, media); ok {
+			configuredID := firstDanmakuEpisodeID(matched)
+			target = strconv.FormatInt(configuredID, 10)
+			targetBase = base
+			res.AnimeTitle = matched[0].AnimeTitle
+			res.EpisodeTitle = matched[0].Episodes[0].EpisodeTitle
+			res.EpisodeID = configuredID
+			res.MatchMode = "metadata"
+			if len(matched) > 1 {
+				res.Alternatives = matched
+			}
+		}
+	}
+
+	// 3) 按播放的文件名 + 集数搜索（keyword 手动覆盖时跳过，直接走第 4 层）。
 	if target == "" && !manualKeyword && media != nil && media.Path != "" {
 		if fileName := danmakuMatchFileName(media.Path); fileName != "" && fileName != term.name {
-			if candidates, err := s.searchCandidatesWithFallback(ctx, configured, official, fileName, term.episode); err == nil &&
+			if candidates, base, err := s.searchCandidatesWithSource(ctx, configured, official, fileName, term.episode); err == nil &&
 				len(candidates) == 1 && len(candidates[0].Episodes) > 0 {
 				target = fmt.Sprintf("%d", candidates[0].Episodes[0].EpisodeID)
+				targetBase = base
 				res.AnimeTitle = candidates[0].AnimeTitle
 				res.EpisodeTitle = candidates[0].Episodes[0].EpisodeTitle
 				res.EpisodeID = candidates[0].Episodes[0].EpisodeID
@@ -273,10 +535,10 @@ func (s *DanmakuService) Fetch(ctx context.Context, mediaID, keyword, episodeID
 		}
 	}
 
-	// 3) 现有自动识别：标题层级（original_name → title → 文件名）+ 集数，
+	// 4) 现有自动识别：标题层级（original_name → title → 文件名）+ 集数，
 	//    多结果返回候选列表交给播放器（歧义处理）。
 	if target == "" {
-		candidates, err := s.searchCandidatesWithFallback(ctx, configured, official, term.name, term.episode)
+		candidates, base, err := s.searchCandidatesWithSource(ctx, configured, official, term.name, term.episode)
 		if err != nil {
 			s.log.Warn("danmaku search failed", zap.String("media_id", mediaID), zap.String("name", term.name), zap.String("episode", term.episode), zap.Error(err))
 			return res, err
@@ -289,21 +551,159 @@ func (s *DanmakuService) Fetch(ctx context.Context, mediaID, keyword, episodeID
 			return res, errors.New("no danmaku library found for this video")
 		}
 		target = fmt.Sprintf("%d", candidates[0].Episodes[0].EpisodeID)
+		targetBase = base
 		res.AnimeTitle = candidates[0].AnimeTitle
 		res.EpisodeTitle = candidates[0].Episodes[0].EpisodeTitle
 		res.EpisodeID = candidates[0].Episodes[0].EpisodeID
 		res.MatchMode = "search"
 	}
 
-	raw, st, err := s.fetchCommentWithFallback(ctx, configured, official, target)
+	raw, st, err := s.fetchCommentWithFallback(ctx, targetBase, official, target)
 	if err != nil {
 		s.log.Warn("danmaku comment fetch failed", zap.String("media_id", mediaID), zap.String("episode_id", target), zap.Error(err))
 		return res, err
 	}
+	// 第三方目录里存在该集，不代表它真的收录了弹幕（实测部分条目返回
+	// count=0）。这种「拿到空库」的情况要用官方 episodeId 再试一次，否则
+	// 重定位后反而会静默变成无弹幕 —— 旧写法是靠官方 ID 撞 404 才走到官方
+	// 兜底的，改用重定位就必须显式补上这一步。
+	if hashOfficialID != 0 && danmakuCommentCount(raw) == 0 {
+		officialTarget := strconv.FormatInt(hashOfficialID, 10)
+		if officialRaw, officialType, officialErr := s.fetchCommentFromBase(ctx, official, officialTarget); officialErr == nil &&
+			danmakuCommentCount(officialRaw) > 0 {
+			raw, st = officialRaw, officialType
+			res.EpisodeID = hashOfficialID
+		} else if officialErr != nil {
+			s.log.Debug("danmaku official fallback for empty configured library failed",
+				zap.String("episode_id", officialTarget), zap.Error(officialErr))
+		}
+	}
+	// 合并多来源：仅在上游确实返回了多个同集来源时才有意义。
+	if opts.MergeSources && len(res.Alternatives) > 1 {
+		if mergedRaw, mergedCount, ok := s.mergeAlternativeSources(ctx, targetBase, res.Alternatives, res.EpisodeID, raw); ok {
+			raw, st = mergedRaw, "json"
+			res.MergedSources = mergedCount
+		}
+	}
 	res.Raw, res.SourceType = raw, st
 	return res, nil
 }
 
+// mergeAlternativeSources 并发抓取同一集的多个来源，按「时间 + 内容」去重后
+// 合并成单个载荷。已有载荷（existingRaw）会被复用，避免重复请求。
+// 返回合并后的载荷、实际参与合并的来源数与是否成功。
+func (s *DanmakuService) mergeAlternativeSources(ctx context.Context, base string, alternatives []DanmakuAnime, existingID int64, existingRaw string) (string, int, bool) {
+	ids := make([]int64, 0, len(alternatives)+1)
+	seen := map[int64]bool{}
+	if existingID > 0 {
+		seen[existingID] = true
+		ids = append(ids, existingID)
+	}
+	for _, anime := range alternatives {
+		for _, ep := range anime.Episodes {
+			if ep.EpisodeID <= 0 || seen[ep.EpisodeID] {
+				continue
+			}
+			seen[ep.EpisodeID] = true
+			ids = append(ids, ep.EpisodeID)
+			if len(ids) >= danmakuMergeMaxSources {
+				break
+			}
+		}
+		if len(ids) >= danmakuMergeMaxSources {
+			break
+		}
+	}
+	// 少于两个来源时无需合并。
+	if len(ids) < 2 {
+		return "", 0, false
+	}
+
+	var (
+		mu        sync.Mutex
+		collected [][]danmakuComment
+		wg        sync.WaitGroup
+		sem       = make(chan struct{}, danmakuMergeConcurrency)
+	)
+	collect := func(raw string) {
+		comments := parseDanmakuComments(raw)
+		if len(comments) == 0 {
+			return
+		}
+		mu.Lock()
+		collected = append(collected, comments)
+		mu.Unlock()
+	}
+	for _, id := range ids {
+		if id == existingID && existingRaw != "" {
+			collect(existingRaw)
+			continue
+		}
+		wg.Add(1)
+		go func(id int64) {
+			defer wg.Done()
+			sem <- struct{}{}
+			defer func() { <-sem }()
+			body, _, err := s.fetchCommentFromBase(ctx, base, strconv.FormatInt(id, 10))
+			if err != nil {
+				// 单个来源失败不影响整体合并，静默跳过。
+				return
+			}
+			collect(body)
+		}(id)
+	}
+	wg.Wait()
+
+	if len(collected) < 2 {
+		return "", 0, false
+	}
+	merged := mergeDanmakuComments(collected)
+	if len(merged) == 0 {
+		return "", 0, false
+	}
+	encoded := encodeDanmakuComments(merged)
+	if encoded == "" {
+		return "", 0, false
+	}
+	return encoded, len(collected), true
+}
+
+// fetchCommentFromBase 从单个源拉取弹幕，不做任何回退。
+func (s *DanmakuService) fetchCommentFromBase(ctx context.Context, base, target string) (raw, sourceType string, err error) {
+	raw, err = s.fetchBody(ctx, fmt.Sprintf("%s/api/v2/comment/%s?withRelated=true", base, target), true)
+	if err != nil {
+		return "", "auto", err
+	}
+	return raw, detectDanmakuSourceType(raw), nil
+}
+
+// danmakuCommentCount 估算弹幕条数，用于判断某个源是否真的返回了内容。
+// 同时兼容 dandanplay JSON 与 Bilibili XML 两种载荷。
+func danmakuCommentCount(raw string) int {
+	trimmed := strings.TrimSpace(raw)
+	if trimmed == "" {
+		return 0
+	}
+	switch {
+	case strings.HasPrefix(trimmed, "{"):
+		var payload struct {
+			Count    int               `json:"count"`
+			Comments []json.RawMessage `json:"comments"`
+		}
+		if err := json.Unmarshal([]byte(trimmed), &payload); err != nil {
+			return 0
+		}
+		if payload.Count > 0 {
+			return payload.Count
+		}
+		return len(payload.Comments)
+	case strings.HasPrefix(trimmed, "<"):
+		return strings.Count(trimmed, "<d ")
+	default:
+		return 0
+	}
+}
+
 // detectDanmakuSourceType guesses the comment payload format from its body.
 // The dandanplay protocol historically returned Bilibili-style XML, but newer
 // and self-hosted implementations return the dandanplay JSON shape
@@ -724,7 +1124,10 @@ type danmakuMatch struct {
 
 // matchOfficial identifies the video via POST /api/v2/match on the official
 // endpoint (always official, signed with the app credentials). Returns the
-// candidate list; empty means nothing matched.
+// candidate list only when the upstream explicitly reports a confident match;
+// empty means nothing matched. The API may return fuzzy suggestions together
+// with isMatched=false; those are not safe to auto-select because their first
+// item can belong to an unrelated anime.
 //
 // fileName must be URL-escaped: the official API rejects raw non-ASCII file
 // names with errorCode 2 (verified against the live API — QueryEscape's
@@ -774,13 +1177,14 @@ func (s *DanmakuService) matchOfficial(ctx context.Context, fileName, fileHash s
 		return nil, fmt.Errorf("danmaku match returned HTTP %d", resp.StatusCode)
 	}
 	var out struct {
-		Success bool           `json:"success"`
-		Matches []danmakuMatch `json:"matches"`
+		Success   bool           `json:"success"`
+		IsMatched bool           `json:"isMatched"`
+		Matches   []danmakuMatch `json:"matches"`
 	}
 	if err := json.Unmarshal(raw, &out); err != nil {
 		return nil, fmt.Errorf("danmaku match returned invalid JSON: %w", err)
 	}
-	if !out.Success {
+	if !out.Success || !out.IsMatched {
 		return nil, nil
 	}
 	return out.Matches, nil
@@ -794,13 +1198,14 @@ func sameDanmakuBase(a, b string) bool {
 	return errA == nil && errB == nil && strings.EqualFold(ua.Host, ub.Host)
 }
 
-// fetchCommentWithFallback fetches a comment library from the configured
-// source first (when set and different from official), falling back to the
-// official endpoint on failure.
-func (s *DanmakuService) fetchCommentWithFallback(ctx context.Context, configured, official, target string) (raw, sourceType string, err error) {
+// fetchCommentWithFallback fetches a comment library from primary first (when
+// set and different from official), falling back to the official endpoint on
+// failure. primary must be the source that issued target: episode ids are only
+// meaningful inside the source that produced them.
+func (s *DanmakuService) fetchCommentWithFallback(ctx context.Context, primary, official, target string) (raw, sourceType string, err error) {
 	var bases []string
-	if configured != "" && !sameDanmakuBase(configured, official) {
-		bases = append(bases, configured)
+	if primary != "" && !sameDanmakuBase(primary, official) {
+		bases = append(bases, primary)
 	}
 	bases = append(bases, official)
 	var lastErr error
@@ -817,16 +1222,301 @@ func (s *DanmakuService) fetchCommentWithFallback(ctx context.Context, configure
 	return "", "auto", lastErr
 }
 
-// searchCandidatesWithFallback searches the configured source first (when
-// set and different from official), falling back to the official endpoint on
-// failure.
-func (s *DanmakuService) searchCandidatesWithFallback(ctx context.Context, configured, official, name, episode string) ([]DanmakuAnime, error) {
+// searchCandidatesWithSource searches the configured source first (when set
+// and different from official), falling back to the official endpoint on
+// failure. It also reports which base produced the hits, because the caller
+// must fetch comments from that same base — episode ids are source-local.
+func (s *DanmakuService) searchCandidatesWithSource(ctx context.Context, configured, official, name, episode string) ([]DanmakuAnime, string, error) {
 	if configured != "" && !sameDanmakuBase(configured, official) {
 		candidates, err := s.searchCandidates(ctx, configured, name, episode)
 		if err == nil {
-			return candidates, nil
+			return candidates, configured, nil
 		}
 		s.log.Warn("danmaku search failed on configured source, falling back to official", zap.String("source", configured), zap.Error(err))
 	}
-	return s.searchCandidates(ctx, official, name, episode)
+	candidates, err := s.searchCandidates(ctx, official, name, episode)
+	return candidates, official, err
+}
+
+// danmakuEpisodeNumberRE 从「第N话 / 第N話 / 第N集」里取出集数。各源标题格式
+// 不一（有的只有集数、有的带副标题），正则只认集数标记本身。
+var danmakuEpisodeNumberRE = regexp.MustCompile(`第\s*(\d+(?:\.\d+)?)\s*[话話集]`)
+
+// danmakuTitleYearRE 匹配搜索源标题里的年份，例如「命运石之门(2011)」。
+var danmakuTitleYearRE = regexp.MustCompile(`\((?:19|20)\d{2}\)`)
+
+// danmakuEpisodeNumber 返回标题中的集数，取不到时返回空串。
+func danmakuEpisodeNumber(title string) string {
+	m := danmakuEpisodeNumberRE.FindStringSubmatch(title)
+	if len(m) < 2 {
+		return ""
+	}
+	return m[1]
+}
+
+// danmakuEpisodeSubtitle 返回「第N话」之后的副标题，用于区分同名前作/续作。
+func danmakuEpisodeSubtitle(title string) string {
+	loc := danmakuEpisodeNumberRE.FindStringIndex(title)
+	if loc == nil {
+		return ""
+	}
+	return strings.TrimSpace(title[loc[1]:])
+}
+
+// normalizeDanmakuText 去掉标点与空白，便于跨源比对副标题。注意它只做字符
+// 归一化，不剥离集数标记 —— 调用方传入的可能已经是剥离后的副标题。
+func normalizeDanmakuText(s string) []rune {
+	out := make([]rune, 0, 32)
+	for _, r := range strings.ToLower(s) {
+		if unicode.IsLetter(r) || unicode.IsDigit(r) {
+			out = append(out, r)
+		}
+	}
+	return out
+}
+
+// danmakuTitleYear 返回标题中显式标注的年份；没有年份时返回 0。
+func danmakuTitleYear(title string) int {
+	m := danmakuTitleYearRE.FindString(title)
+	if len(m) != 6 {
+		return 0
+	}
+	year, _ := strconv.Atoi(m[1:5])
+	return year
+}
+
+// danmakuSubtitleMatches 判断两个源的副标题是否指向同一集。
+//
+// 完全一致直接判定相同，且不设长度门槛 —— 中文副标题常常只有两三个字
+// （「辛」「序曲」），但它们本身就是很强的标识。只有在做包含/前缀这类模糊
+// 比对时才要求足够长度，避免短串误配到别的集。同一集在不同源的副标题长度
+// 也可能不同（一侧带 "-Fractal Androgynous-" 之类后缀），故保留模糊分支。
+func danmakuSubtitleMatches(candidateTitle, subtitle string) bool {
+	// candidateTitle 是完整标题，subtitle 已经剥离过集数标记，两者处理方式不同。
+	a := normalizeDanmakuText(danmakuEpisodeSubtitle(candidateTitle))
+	b := normalizeDanmakuText(subtitle)
+	if len(a) == 0 || len(b) == 0 {
+		return false
+	}
+	if string(a) == string(b) {
+		return true
+	}
+	const fuzzyMinRunes = 4
+	if len(a) < fuzzyMinRunes || len(b) < fuzzyMinRunes {
+		return false
+	}
+	if strings.Contains(string(a), string(b)) || strings.Contains(string(b), string(a)) {
+		return true
+	}
+	if danmakuRuneSimilarity(a, b) >= 0.7 {
+		return true
+	}
+	n := len(a)
+	if len(b) < n {
+		n = len(b)
+	}
+	if n > 12 {
+		n = 12
+	}
+	return string(a[:n]) == string(b[:n])
+}
+
+// danmakuRuneSimilarity 返回两个字符串的 LCS 相似度，分母取较短长度。
+// 弹幕源的日文/英文副标题常比刮削标题更长，因此不能直接用整体编辑距离；
+// 例如「起始与终结的序章」和「始与终的序章-Turning Point-」应被视为同一集。
+func danmakuRuneSimilarity(a, b []rune) float64 {
+	if len(a) == 0 || len(b) == 0 {
+		return 0
+	}
+	prev := make([]int, len(b)+1)
+	for _, ra := range a {
+		cur := make([]int, len(b)+1)
+		for j, rb := range b {
+			if ra == rb {
+				cur[j+1] = prev[j] + 1
+			} else if cur[j] > prev[j+1] {
+				cur[j+1] = cur[j]
+			} else {
+				cur[j+1] = prev[j+1]
+			}
+		}
+		prev = cur
+	}
+	minLen := len(a)
+	if len(b) < minLen {
+		minLen = len(b)
+	}
+	return float64(prev[len(b)]) / float64(minLen)
+}
+
+// lookupConfiguredEpisodes 用官方 match 给出的「剧名 + 集数」在配置源里重新
+// 定位同一集，返回配置源里所有指向该集的结果。
+//
+// 必须重定位：各源 episodeId 空间互相独立，官方 ID（如 135500001）在第三方
+// 源上只是一个不存在的编号，直接请求必然 404。官方 match 返回的 animeTitle /
+// episodeTitle 正好提供了跨源检索所需的剧名、集数与副标题。
+//
+// 返回列表而非单条：LogVar 这类源聚合了多个视频网站，同一集常有多个库，
+// 调用方取第一条自动加载，其余作为可切换来源交给用户。
+func (s *DanmakuService) lookupConfiguredEpisodes(ctx context.Context, configured string, m danmakuMatch) ([]DanmakuAnime, bool) {
+	episodeNum := danmakuEpisodeNumber(m.EpisodeTitle)
+	if episodeNum == "" || strings.TrimSpace(m.AnimeTitle) == "" {
+		return nil, false
+	}
+	candidates, err := s.searchCandidates(ctx, configured, m.AnimeTitle, episodeNum)
+	if err != nil {
+		s.log.Debug("danmaku configured lookup failed",
+			zap.String("source", configured),
+			zap.String("anime", m.AnimeTitle),
+			zap.Error(err))
+		return nil, false
+	}
+	matched := matchDanmakuEpisodes(candidates, episodeNum, m.EpisodeTitle)
+	if len(matched) == 0 {
+		return nil, false
+	}
+	return matched, true
+}
+
+// lookupScrapedEpisodes uses already-scraped media metadata to locate the
+// correct library when hash identification missed. Unlike the generic title
+// search, this path requires an explicit episode-title match and, when known,
+// a matching release year. That prevents Steins;Gate (2011) from being
+// confused with Steins;Gate 0 (2018) or other same-name entries.
+func (s *DanmakuService) lookupScrapedEpisodes(ctx context.Context, configured, official string, media *model.Media) ([]DanmakuAnime, string, bool) {
+	title, episodeNum, episodeTitle, ok := scrapedDanmakuMetadata(media)
+	if !ok {
+		return nil, "", false
+	}
+	candidates, base, err := s.searchCandidatesWithSource(ctx, configured, official, title, episodeNum)
+	if err != nil {
+		s.log.Debug("danmaku scraped metadata lookup failed",
+			zap.String("title", title),
+			zap.String("episode", episodeNum),
+			zap.Error(err))
+		return nil, "", false
+	}
+	matched := matchScrapedDanmakuEpisodes(candidates, title, media.Year, episodeNum, episodeTitle)
+	if len(matched) == 0 {
+		return nil, "", false
+	}
+	return matched, base, true
+}
+
+// scrapedDanmakuMetadata returns the query fields only when the media has
+// enough scraped information to identify a specific episode.
+func scrapedDanmakuMetadata(media *model.Media) (title, episodeNum, episodeTitle string, ok bool) {
+	if media == nil {
+		return "", "", "", false
+	}
+	title = strings.TrimSpace(media.Title)
+	if title == "" {
+		title = strings.TrimSpace(media.OriginalName)
+	}
+	episodeTitle = strings.TrimSpace(media.EpisodeTitle)
+	if title == "" || media.EpisodeNum <= 0 || episodeTitle == "" {
+		return "", "", "", false
+	}
+	return title, strconv.Itoa(media.EpisodeNum), episodeTitle, true
+}
+
+// matchScrapedDanmakuEpisodes filters title search hits by release year and
+// episode subtitle. The returned list keeps the source grouping so multiple
+// libraries for the same episode remain switchable in the player.
+func matchScrapedDanmakuEpisodes(candidates []DanmakuAnime, title string, year int, episodeNum, episodeTitle string) []DanmakuAnime {
+	out := make([]DanmakuAnime, 0, len(candidates))
+	for _, anime := range candidates {
+		if !danmakuAnimeTitleMatches(anime.AnimeTitle, title, year) {
+			continue
+		}
+		hits := matchDanmakuEpisodeHits(anime.Episodes, episodeNum, episodeTitle)
+		if len(hits) == 0 {
+			continue
+		}
+		anime.Episodes = hits
+		out = append(out, anime)
+	}
+	return out
+}
+
+// danmakuAnimeTitleMatches checks the scraped title and, when present, the
+// candidate's year. A candidate with a conflicting explicit year is rejected
+// even if its title contains the scraped title.
+func danmakuAnimeTitleMatches(animeTitle, mediaTitle string, year int) bool {
+	candidate := string(normalizeDanmakuText(animeTitle))
+	target := string(normalizeDanmakuText(mediaTitle))
+	if candidate == "" || target == "" || !strings.Contains(candidate, target) {
+		return false
+	}
+	if year > 0 {
+		if candidateYear := danmakuTitleYear(animeTitle); candidateYear > 0 && candidateYear != year {
+			return false
+		}
+	}
+	return true
+}
+
+// firstDanmakuEpisodeID 返回匹配列表里的第一条 episodeId，作为自动选中的库。
+func firstDanmakuEpisodeID(matched []DanmakuAnime) int64 {
+	for _, anime := range matched {
+		for _, ep := range anime.Episodes {
+			if ep.EpisodeID > 0 {
+				return ep.EpisodeID
+			}
+		}
+	}
+	return 0
+}
+
+// pickDanmakuEpisodeID 从配置源的搜索结果里挑出与目标集最匹配的一条。
+//
+// 搜索按「剧名+集数」返回，但同名不同季/不同版本会同时命中，且顺序不保证
+// 正确：实测「命运石之门 第18话」首条是《命运石之门 0(2018)》、《战区88 OVA
+// 第1话》首条是《战区88(2004) TV》，两者内容都不对，只有副标题能区分。因此：
+//   - 目标带副标题时，必须找到副标题一致的候选，否则放弃（宁可回退官方，
+//     也不能给用户放错番的弹幕）；
+//   - 目标没有副标题（如「第11话」）时，退而要求集数一致。
+func pickDanmakuEpisodeID(candidates []DanmakuAnime, episodeNum, episodeTitle string) (int64, bool) {
+	if id := firstDanmakuEpisodeID(matchDanmakuEpisodes(candidates, episodeNum, episodeTitle)); id != 0 {
+		return id, true
+	}
+	return 0, false
+}
+
+// matchDanmakuEpisodes 在搜索结果里筛出所有指向目标集的结果，保留原有的番剧
+// 分组结构（只留下命中的集数），因此调用方既能取第一条自动加载，也能把整个
+// 列表作为可切换来源展示。
+func matchDanmakuEpisodes(candidates []DanmakuAnime, episodeNum, episodeTitle string) []DanmakuAnime {
+	out := make([]DanmakuAnime, 0, len(candidates))
+	for _, anime := range candidates {
+		hits := matchDanmakuEpisodeHits(anime.Episodes, episodeNum, episodeTitle)
+		if len(hits) == 0 {
+			continue
+		}
+		anime.Episodes = hits
+		out = append(out, anime)
+	}
+	return out
+}
+
+// matchDanmakuEpisodeHits 返回同一番剧里指向目标集的弹幕库。
+func matchDanmakuEpisodeHits(episodes []DanmakuEpisode, episodeNum, episodeTitle string) []DanmakuEpisode {
+	subtitle := danmakuEpisodeSubtitle(episodeTitle)
+	// 刮削后的 episode_title 通常只保存副标题本身（例如「起始与终结的序章」），
+	// 不带「第1话」前缀。此时把它整体作为副标题参与比对。
+	if subtitle == "" && danmakuEpisodeNumber(episodeTitle) == "" {
+		subtitle = strings.TrimSpace(episodeTitle)
+	}
+	hits := make([]DanmakuEpisode, 0, len(episodes))
+	for _, ep := range episodes {
+		if ep.EpisodeID <= 0 || danmakuEpisodeNumber(ep.EpisodeTitle) != episodeNum {
+			continue
+		}
+		// 目标带副标题时必须副标题一致；没有副标题时仅凭集数匹配。
+		if subtitle != "" && !danmakuSubtitleMatches(ep.EpisodeTitle, subtitle) {
+			continue
+		}
+		hits = append(hits, ep)
+	}
+	return hits
 }

internal/service/danmaku_service_test.go

@@ -6,6 +6,8 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"path/filepath"
+	"sync"
+	"sync/atomic"
 	"testing"
 
 	"github.com/glebarez/sqlite"
@@ -22,7 +24,8 @@ func newDanmakuTestService(t *testing.T) *DanmakuService {
 	// 独立临时文件库，避免测试间通过共享内存库串数据。
 	db, err := gorm.Open(sqlite.Open(filepath.Join(t.TempDir(), "danmaku-test.db")), &gorm.Config{})
 	require.NoError(t, err)
-	require.NoError(t, db.AutoMigrate(&model.Setting{}, &model.Media{}))
+	// 需要 users 表：弹幕合并偏好按用户存储在 user 行上。
+	require.NoError(t, db.AutoMigrate(&model.Setting{}, &model.Media{}, &model.User{}))
 	repos := repository.New(db)
 	t.Cleanup(func() {
 		sqlDB, err := db.DB()
@@ -325,3 +328,79 @@ func TestDanmakuFetchDetectsJSONSource(t *testing.T) {
 	require.Equal(t, "xml", res2.SourceType)
 	require.Contains(t, res2.Raw, "弹幕A")
 }
+
+// 同一集在缓存 TTL 内重复请求时不应再访问上游（搜索和评论都只发一次）。
+func TestDanmakuFetchCachesRepeatedRequests(t *testing.T) {
+	var searchCalls, commentCalls int32
+	mux := http.NewServeMux()
+	mux.HandleFunc("/api/v2/search/episodes", func(w http.ResponseWriter, r *http.Request) {
+		atomic.AddInt32(&searchCalls, 1)
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"hasMore":false,"animes":[{"animeId":1001,"animeTitle":"测试动画","episodes":[{"episodeId":25484,"episodeTitle":"第1话"}]}]}`)
+	})
+	mux.HandleFunc("/api/v2/comment/25484", func(w http.ResponseWriter, r *http.Request) {
+		atomic.AddInt32(&commentCalls, 1)
+		w.Header().Set("Content-Type", "application/xml")
+		fmt.Fprint(w, `<?xml version="1.0"?><i><d p="0.5,1,16777215,user1">缓存测试</d></i>`)
+	})
+	srv := httptest.NewServer(mux)
+	defer srv.Close()
+
+	svc := newDanmakuTestService(t)
+	ctx := context.Background()
+	require.NoError(t, svc.repo.Setting.Set(ctx, DanmakuSourceKey, srv.URL))
+	seedDanmakuMedia(t, svc, "cache-media", "测试动画", "", 1)
+
+	first, err := svc.Fetch(ctx, "cache-media", "", "")
+	require.NoError(t, err)
+	require.NotEmpty(t, first.Raw)
+
+	second, err := svc.Fetch(ctx, "cache-media", "", "")
+	require.NoError(t, err)
+	require.Equal(t, first.Raw, second.Raw)
+	require.EqualValues(t, 1, atomic.LoadInt32(&searchCalls))
+	require.EqualValues(t, 1, atomic.LoadInt32(&commentCalls))
+}
+
+// 并发的同一集请求应被 singleflight 合并，上游只被访问一次。
+func TestDanmakuFetchCoalescesConcurrentRequests(t *testing.T) {
+	var searchCalls int32
+	mux := http.NewServeMux()
+	mux.HandleFunc("/api/v2/search/episodes", func(w http.ResponseWriter, r *http.Request) {
+		atomic.AddInt32(&searchCalls, 1)
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"hasMore":false,"animes":[{"animeId":1001,"animeTitle":"测试动画","episodes":[{"episodeId":25484,"episodeTitle":"第1话"}]}]}`)
+	})
+	mux.HandleFunc("/api/v2/comment/25484", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/xml")
+		fmt.Fprint(w, `<?xml version="1.0"?><i><d p="0.5,1,16777215,user1">并发测试</d></i>`)
+	})
+	srv := httptest.NewServer(mux)
+	defer srv.Close()
+
+	svc := newDanmakuTestService(t)
+	ctx := context.Background()
+	require.NoError(t, svc.repo.Setting.Set(ctx, DanmakuSourceKey, srv.URL))
+	seedDanmakuMedia(t, svc, "concurrent-media", "测试动画", "", 1)
+
+	const workers = 8
+	start := make(chan struct{})
+	errs := make(chan error, workers)
+	var wg sync.WaitGroup
+	for i := 0; i < workers; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			<-start
+			_, err := svc.Fetch(ctx, "concurrent-media", "", "")
+			errs <- err
+		}()
+	}
+	close(start)
+	wg.Wait()
+	close(errs)
+	for err := range errs {
+		require.NoError(t, err)
+	}
+	require.EqualValues(t, 1, atomic.LoadInt32(&searchCalls))
+}

internal/service/emby_artwork.go

@@ -32,17 +32,14 @@ func (e *EmbyService) ImageURL(ctx context.Context, id, imageType string) (strin
 		}
 		return backdrop
 	}
-	if strings.HasPrefix(id, embyVirtualSeasonPrefix) {
+	if strings.HasPrefix(id, embyVirtualSeasonPrefix) || strings.HasPrefix(id, embyVirtualSeriesPrefix) {
 		if raw, ok := e.cachedArtworkURL(id, imageType); ok {
 			return raw, nil
 		}
-		return "", nil
-	}
-	if strings.HasPrefix(id, embyVirtualSeriesPrefix) {
-		if raw, ok := e.cachedArtworkURL(id, imageType); ok {
-			return raw, nil
-		}
-		return "", nil
+		// Latest JSON can outlive (or be served after) the in-memory artwork
+		// map. Rebuild from the library instead of handing the client a 1x1
+		// placeholder that it then caches as a successful image.
+		return e.resolveVirtualArtwork(ctx, id, imageType, pick)
 	}
 	m, err := e.repo.Media.FindByID(ctx, id)
 	if err == nil && m != nil {
@@ -71,6 +68,69 @@ func (e *EmbyService) ImageURL(ctx context.Context, id, imageType string) (strin
 	return "", nil
 }
 
+func (e *EmbyService) resolveVirtualArtwork(ctx context.Context, id, imageType string, pick func(primary, backdrop string) string) (string, error) {
+	if strings.HasPrefix(id, embyVirtualSeasonPrefix) {
+		season, ok, err := e.findSeasonGroup(ctx, id, "")
+		if err != nil || !ok {
+			return "", err
+		}
+		return pick(season.Series.PosterURL, season.Series.BackdropURL), nil
+	}
+	series, ok, err := e.findSeriesGroup(ctx, id, "")
+	if err != nil || !ok {
+		return "", err
+	}
+	return pick(series.PosterURL, series.BackdropURL), nil
+}
+
+// imageInfoTypes 是 GET /Items/{Id}/Images 会报告的图片类型。只列 MeBox
+// 真正存储的两类：ImageURL 对 Thumb / Logo / Banner 等其余类型会回退到
+// 主图，若一并列出会让客户端以为存在这些图并去请求，实际拿到的却是主图。
+var imageInfoTypes = []string{"Primary", "Backdrop"}
+
+// ImageInfos 返回条目的图片清单，对应 Emby 的 GET /Items/{Id}/Images。
+// 客户端用它在详情页决定要加载哪些图；缺失该接口会落到 404，部分客户端
+// 因此把条目当成"无图"而放弃渲染海报。
+func (e *EmbyService) ImageInfos(ctx context.Context, id string) []map[string]any {
+	id = strings.TrimSpace(id)
+	if id == "" {
+		return nil
+	}
+	out := make([]map[string]any, 0, 2)
+	seen := map[string]bool{}
+	for _, imageType := range imageInfoTypes {
+		raw, err := e.ImageURL(ctx, id, imageType)
+		if err != nil {
+			continue
+		}
+		raw = strings.TrimSpace(raw)
+		// 非 Backdrop 类型在缺图时会回退到主图，去重避免同一张图重复出现。
+		if raw == "" || seen[raw] {
+			continue
+		}
+		seen[raw] = true
+		out = append(out, map[string]any{
+			"ImageType":  imageType,
+			"ImageIndex": 0,
+			"ImageTag":   id,
+		})
+	}
+	return out
+}
+
+// UserAvatarURL 返回用户头像的来源地址；用户未设置头像时返回空串。
+func (e *EmbyService) UserAvatarURL(ctx context.Context, userID string) string {
+	userID = strings.TrimSpace(userID)
+	if userID == "" || e == nil || e.repo == nil || e.repo.User == nil {
+		return ""
+	}
+	user, err := e.repo.User.FindByID(ctx, userID)
+	if err != nil || user == nil {
+		return ""
+	}
+	return strings.TrimSpace(user.AvatarURL)
+}
+
 // cachedLibraryCover returns a previously resolved library cover URL within TTL.
 func (e *EmbyService) cachedLibraryCover(id string) (string, bool) {
 	if e == nil || strings.TrimSpace(id) == "" {

internal/service/emby_compat.go

@@ -117,6 +117,18 @@ const (
 	embyVirtualCacheTTL     = 10 * time.Minute
 	embyVisibilityCacheTTL  = 30 * time.Second
 	embySeriesGroupingLimit = maxMediaSearchLimit
+	// Virtual artwork used to be wiped entirely once the in-memory map crossed
+	// a few thousand entries. A homepage refresh asks Latest for every library
+	// at once, so that wipe dropped the series the client was about to paint.
+	// Caps are sized for that fan-out; overflow evicts the oldest entries only.
+	embyVirtualSeriesCap  = 8000
+	embyVirtualSeasonCap  = 16000
+	embyVirtualArtworkCap = 24000
+	// Clients that already cached the 1x1 placeholder treat a stable tag as
+	// immutable. Virtual ids are the ones that served that placeholder, so
+	// only those tags get a suffix that forces a refetch.
+	embyVirtualPrimaryTagSuffix  = "-p2"
+	embyVirtualBackdropTagSuffix = "-bd2"
 )
 
 var (

internal/service/emby_items_cache.go

@@ -15,7 +15,8 @@ type embyItemsCacheValue struct {
 }
 
 type embyLatestCacheValue struct {
-	Items []map[string]any `json:"items"`
+	Items   []map[string]any          `json:"items"`
+	Artwork map[string]embyArtworkRef `json:"artwork,omitempty"`
 }
 
 func (e *EmbyService) embyItemsCacheKey(kind string, p ItemsParams) string {
@@ -43,10 +44,25 @@ func (e *EmbyService) embyItemsCacheKey(kind string, p ItemsParams) string {
 }
 
 func (e *EmbyService) embyLatestCacheKey(userID, parentID string, limit int) string {
-	sum := sha256.Sum256([]byte(strings.Join([]string{"latest", userID, parentID, strconv.Itoa(limit)}, "|")))
+	// v2: payload tags for virtual artwork changed so clients drop cached placeholders.
+	sum := sha256.Sum256([]byte(strings.Join([]string{"latest-v2", userID, parentID, strconv.Itoa(limit)}, "|")))
 	return "media:emby:" + hex.EncodeToString(sum[:])
 }
 
+// defaultEmbyLatestCacheTTLSeconds 是 Emby「最新添加」缓存的兜底时长。
+const defaultEmbyLatestCacheTTLSeconds = 300
+
+// embyLatestCacheTTLSeconds 返回「最新添加」列表的缓存时长。它刻意比通用
+// 媒体缓存更长：客户端刷新首页时会同时请求全部媒体库的 Latest（生产环境
+// 观察到 73 个并发），缓存一旦集中过期，这批请求会同时穿透并各自重建
+// payload。延长后稳态下几乎全部命中缓存，冷启动频率也随之下降。
+func (e *EmbyService) embyLatestCacheTTLSeconds() int {
+	if e == nil || e.cfg == nil || e.cfg.Cache.EmbyLatestTTLSeconds < 1 {
+		return defaultEmbyLatestCacheTTLSeconds
+	}
+	return e.cfg.Cache.EmbyLatestTTLSeconds
+}
+
 func (e *EmbyService) mediaCacheTTLSeconds() int {
 	if e == nil || e.cfg == nil || e.cfg.Cache.MediaTTLSeconds < 1 {
 		return 90

internal/service/emby_items_detail.go

@@ -132,15 +132,16 @@ func (e *EmbyService) LatestItems(ctx context.Context, userID, parentID string,
 	cacheKey := e.embyLatestCacheKey(userID, parentID, limit)
 	var cached embyLatestCacheValue
 	if e.cache != nil && e.cache.GetJSON(ctx, cacheKey, &cached) {
+		e.rememberArtworkRefs(cached.Artwork)
 		return cached.Items, nil
 	}
 	q := e.repo.DB.WithContext(ctx).Model(&model.Media{}).Where("deleted_at IS NULL")
 	q = e.applyUserMediaVisibility(ctx, q, userID)
 	if parentID != "" {
 		if episodic, err := e.libraryIsEpisodic(ctx, parentID); err == nil && episodic {
-			out, err := e.latestSeriesItemsForLibrary(ctx, userID, parentID, limit)
+			out, artwork, err := e.latestSeriesItemsForLibrary(ctx, userID, parentID, limit)
 			if err == nil && e.cache != nil {
-				e.cache.SetJSON(ctx, cacheKey, embyLatestCacheValue{Items: out}, time.Duration(e.mediaCacheTTLSeconds())*time.Second)
+				e.cache.SetJSON(ctx, cacheKey, embyLatestCacheValue{Items: out, Artwork: artwork}, time.Duration(e.embyLatestCacheTTLSeconds())*time.Second)
 			}
 			return out, err
 		}
@@ -166,12 +167,12 @@ func (e *EmbyService) LatestItems(ctx context.Context, userID, parentID string,
 		return nil, err
 	}
 	if e.cache != nil {
-		e.cache.SetJSON(ctx, cacheKey, embyLatestCacheValue{Items: out}, time.Duration(e.mediaCacheTTLSeconds())*time.Second)
+		e.cache.SetJSON(ctx, cacheKey, embyLatestCacheValue{Items: out}, time.Duration(e.embyLatestCacheTTLSeconds())*time.Second)
 	}
 	return out, nil
 }
 
-func (e *EmbyService) latestSeriesItemsForLibrary(ctx context.Context, userID, libraryID string, limit int) ([]map[string]any, error) {
+func (e *EmbyService) latestSeriesItemsForLibrary(ctx context.Context, userID, libraryID string, limit int) ([]map[string]any, map[string]embyArtworkRef, error) {
 	if limit <= 0 || limit > 100 {
 		limit = 20
 	}
@@ -180,7 +181,7 @@ func (e *EmbyService) latestSeriesItemsForLibrary(ctx context.Context, userID, l
 	q = e.applyUserMediaVisibility(ctx, q, userID)
 	var rows []model.Media
 	if err := q.Order(mediaReleaseOrderSQL(true)).Limit(embySeriesGroupingLimit).Find(&rows).Error; err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 	groups := e.seriesGroupsFromMedia(ctx, rows)
 	sortSeriesGroups(groups, ItemsParams{SortBy: "premieredate", SortOrder: "Descending"})
@@ -191,7 +192,7 @@ func (e *EmbyService) latestSeriesItemsForLibrary(ctx context.Context, userID, l
 	for _, group := range groups {
 		items = append(items, e.seriesPayload(group))
 	}
-	return items, nil
+	return items, e.artworkRefsForSeriesGroups(groups), nil
 }
 
 // ResumeItems 列出有未完成播放进度的媒体。
@@ -519,11 +520,11 @@ func (e *EmbyService) itemPayload(ctx context.Context, m *model.Media, fav bool,
 	if seriesID != "" {
 		if sEntry, ok, _ := e.payloadSeriesEntry(ctx, seriesID); ok {
 			if sEntry.posterURL != "" {
-				item["SeriesPrimaryImageTag"] = seriesID
+				item["SeriesPrimaryImageTag"] = embyVirtualImageTag(seriesID, embyVirtualPrimaryTagSuffix)
 			}
-			if len(backdropTags) == 0 && sEntry.backdropURL != "" {
+			if len(backdropTags) == 0 && (sEntry.backdropURL != "" || sEntry.posterURL != "") {
 				item["ParentBackdropItemId"] = seriesID
-				item["ParentBackdropImageTags"] = []string{seriesID + "-bd"}
+				item["ParentBackdropImageTags"] = []string{embyVirtualImageTag(seriesID, embyVirtualBackdropTagSuffix)}
 			}
 		}
 	}

internal/service/emby_series_cache.go

@@ -1,6 +1,7 @@
 package service
 
 import (
+	"sort"
 	"strings"
 	"time"
 )
@@ -37,11 +38,7 @@ func (e *EmbyService) rememberSeriesGroup(group embySeriesGroup) {
 	if e.virtualArtwork == nil {
 		e.virtualArtwork = make(map[string]embyArtworkCacheEntry)
 	}
-	if len(e.virtualSeries) > 2000 || len(e.virtualSeasons) > 5000 || len(e.virtualArtwork) > 7000 {
-		e.virtualSeries = make(map[string]embySeriesCacheEntry)
-		e.virtualSeasons = make(map[string]embySeasonCacheEntry)
-		e.virtualArtwork = make(map[string]embyArtworkCacheEntry)
-	}
+	e.trimVirtualCachesLocked(time.Now())
 	e.virtualSeries[group.ID] = embySeriesCacheEntry{group: group, expiresAt: expiresAt}
 	e.virtualArtwork[group.ID] = embyArtworkCacheEntry{primary: group.PosterURL, backdrop: group.BackdropURL, expiresAt: expiresAt}
 	e.virtualArtwork[group.ID+"-bd"] = embyArtworkCacheEntry{primary: group.PosterURL, backdrop: group.BackdropURL, expiresAt: expiresAt}
@@ -65,6 +62,7 @@ func (e *EmbyService) rememberSeasonGroup(season embySeasonGroup) {
 	if e.virtualArtwork == nil {
 		e.virtualArtwork = make(map[string]embyArtworkCacheEntry)
 	}
+	e.trimVirtualCachesLocked(time.Now())
 	e.virtualSeasons[season.ID] = embySeasonCacheEntry{season: season, expiresAt: expiresAt}
 	e.virtualArtwork[season.ID] = embyArtworkCacheEntry{primary: season.Series.PosterURL, backdrop: season.Series.BackdropURL, expiresAt: expiresAt}
 	e.virtualArtwork[season.ID+"-bd"] = embyArtworkCacheEntry{primary: season.Series.PosterURL, backdrop: season.Series.BackdropURL, expiresAt: expiresAt}
@@ -135,3 +133,123 @@ func (e *EmbyService) cachedArtworkURL(id, imageType string) (string, bool) {
 	}
 	return entry.backdrop, entry.backdrop != ""
 }
+
+// embyArtworkRef is the poster/backdrop pair stored next to a Latest payload
+// so a JSON-cache hit can refill the in-memory artwork map before the client
+// asks for the image.
+type embyArtworkRef struct {
+	Primary  string `json:"primary,omitempty"`
+	Backdrop string `json:"backdrop,omitempty"`
+}
+
+func (e *EmbyService) artworkRefsForSeriesGroups(groups []embySeriesGroup) map[string]embyArtworkRef {
+	if e == nil || len(groups) == 0 {
+		return nil
+	}
+	refs := make(map[string]embyArtworkRef, len(groups)*2)
+	for _, group := range groups {
+		if group.PosterURL == "" && group.BackdropURL == "" {
+			continue
+		}
+		ref := embyArtworkRef{Primary: group.PosterURL, Backdrop: group.BackdropURL}
+		refs[group.ID] = ref
+		for _, season := range e.seasonsForSeries(group) {
+			refs[season.ID] = ref
+		}
+	}
+	if len(refs) == 0 {
+		return nil
+	}
+	return refs
+}
+
+func (e *EmbyService) rememberArtworkRefs(refs map[string]embyArtworkRef) {
+	if e == nil || len(refs) == 0 {
+		return
+	}
+	expiresAt := time.Now().Add(embyVirtualCacheTTL)
+	e.virtualMu.Lock()
+	defer e.virtualMu.Unlock()
+	if e.virtualArtwork == nil {
+		e.virtualArtwork = make(map[string]embyArtworkCacheEntry, len(refs))
+	}
+	e.trimVirtualArtworkLocked(time.Now())
+	for id, ref := range refs {
+		if strings.TrimSpace(id) == "" || (ref.Primary == "" && ref.Backdrop == "") {
+			continue
+		}
+		e.virtualArtwork[id] = embyArtworkCacheEntry{primary: ref.Primary, backdrop: ref.Backdrop, expiresAt: expiresAt}
+	}
+}
+
+func (e *EmbyService) trimVirtualCachesLocked(now time.Time) {
+	e.trimVirtualSeriesLocked(now)
+	e.trimVirtualSeasonsLocked(now)
+	e.trimVirtualArtworkLocked(now)
+}
+
+func (e *EmbyService) trimVirtualSeriesLocked(now time.Time) {
+	for id, entry := range e.virtualSeries {
+		if now.After(entry.expiresAt) {
+			delete(e.virtualSeries, id)
+		}
+	}
+	evictOldest(e.virtualSeries, embyVirtualSeriesCap, func(entry embySeriesCacheEntry) time.Time {
+		return entry.expiresAt
+	})
+}
+
+func (e *EmbyService) trimVirtualSeasonsLocked(now time.Time) {
+	for id, entry := range e.virtualSeasons {
+		if now.After(entry.expiresAt) {
+			delete(e.virtualSeasons, id)
+		}
+	}
+	evictOldest(e.virtualSeasons, embyVirtualSeasonCap, func(entry embySeasonCacheEntry) time.Time {
+		return entry.expiresAt
+	})
+}
+
+func (e *EmbyService) trimVirtualArtworkLocked(now time.Time) {
+	for id, entry := range e.virtualArtwork {
+		if now.After(entry.expiresAt) {
+			delete(e.virtualArtwork, id)
+		}
+	}
+	evictOldest(e.virtualArtwork, embyVirtualArtworkCap, func(entry embyArtworkCacheEntry) time.Time {
+		return entry.expiresAt
+	})
+}
+
+// evictOldest drops the soonest-expiring entries until the map is under cap.
+// It must not replace the map: a homepage refresh remembers many series at
+// once, and wiping the whole cache made the just-advertised backdrops 404
+// into a 1x1 placeholder.
+func evictOldest[T any](items map[string]T, cap int, expiresAt func(T) time.Time) {
+	excess := len(items) - cap
+	if cap <= 0 || excess <= 0 {
+		return
+	}
+	type pair struct {
+		id string
+		at time.Time
+	}
+	ordered := make([]pair, 0, len(items))
+	for id, entry := range items {
+		ordered = append(ordered, pair{id: id, at: expiresAt(entry)})
+	}
+	sort.Slice(ordered, func(i, j int) bool { return ordered[i].at.Before(ordered[j].at) })
+	if excess > len(ordered) {
+		excess = len(ordered)
+	}
+	for i := 0; i < excess; i++ {
+		delete(items, ordered[i].id)
+	}
+}
+
+func embyVirtualImageTag(id, suffix string) string {
+	if strings.HasPrefix(id, embyVirtualSeriesPrefix) || strings.HasPrefix(id, embyVirtualSeasonPrefix) {
+		return id + suffix
+	}
+	return id
+}

internal/service/emby_series_hierarchy_test.go

@@ -296,6 +296,71 @@ func TestEmbyVirtualSeriesArtworkUsesListCache(t *testing.T) {
 	}
 }
 
+func TestEmbyVirtualSeriesArtworkRebuildsAfterMemoryDrop(t *testing.T) {
+	svc := newTestEmbyService(t)
+	svc.cache = NewRuntimeCacheService(nil, nil)
+	lib := model.Library{Name: "番剧", Path: `/media/anime`, Type: "anime", Enabled: true}
+	if err := svc.repo.Library.Create(t.Context(), &lib); err != nil {
+		t.Fatalf("create library: %v", err)
+	}
+	media := model.Media{
+		Base:        model.Base{ID: "ep-hero"},
+		LibraryID:   lib.ID,
+		Title:       "树海之魔",
+		Path:        `/media/anime/树海之魔/Season 01/树海之魔 - S01E01.mkv`,
+		PosterURL:   `/poster.jpg`,
+		BackdropURL: `/backdrop.jpg`,
+		SeasonNum:   1,
+		EpisodeNum:  1,
+	}
+	if err := svc.repo.DB.Create(&media).Error; err != nil {
+		t.Fatalf("create media: %v", err)
+	}
+
+	items, err := svc.LatestItems(t.Context(), "", lib.ID, 5)
+	if err != nil {
+		t.Fatalf("latest items: %v", err)
+	}
+	if len(items) != 1 {
+		t.Fatalf("latest len = %d, want 1", len(items))
+	}
+	seriesID, _ := items[0]["Id"].(string)
+	tags, _ := items[0]["BackdropImageTags"].([]string)
+	if seriesID == "" || len(tags) != 1 || tags[0] != seriesID+embyVirtualBackdropTagSuffix {
+		t.Fatalf("hero item should advertise a cache-busted backdrop tag, got id=%q tags=%#v", seriesID, items[0]["BackdropImageTags"])
+	}
+
+	svc.virtualMu.Lock()
+	svc.virtualArtwork = nil
+	svc.virtualSeries = nil
+	svc.virtualSeasons = nil
+	svc.virtualMu.Unlock()
+
+	backdrop, err := svc.ImageURL(t.Context(), seriesID, "Backdrop")
+	if err != nil {
+		t.Fatalf("backdrop after memory drop: %v", err)
+	}
+	if backdrop != "/backdrop.jpg" {
+		t.Fatalf("backdrop = %q, want rebuilt backdrop", backdrop)
+	}
+
+	svc.virtualMu.Lock()
+	svc.virtualArtwork = nil
+	svc.virtualMu.Unlock()
+	if _, err := svc.LatestItems(t.Context(), "", lib.ID, 5); err != nil {
+		t.Fatalf("cached latest: %v", err)
+	}
+	cancelled, cancel := context.WithCancel(t.Context())
+	cancel()
+	backdrop, err = svc.ImageURL(cancelled, seriesID, "Backdrop")
+	if err != nil {
+		t.Fatalf("backdrop from rewarmed cache: %v", err)
+	}
+	if backdrop != "/backdrop.jpg" {
+		t.Fatalf("rewarmed backdrop = %q, want cached backdrop", backdrop)
+	}
+}
+
 func TestEmbyCloudAnimeUsesSeriesNameFromChineseSeasonFolder(t *testing.T) {
 	svc := newTestEmbyService(t)
 	lib := model.Library{Name: "OpenList · 国漫", Path: `cloud://openlist/国漫`, Type: "anime", Enabled: true}
@@ -429,13 +494,13 @@ func TestInferSeriesNameFromPath(t *testing.T) {
 			want: "间谍过家家",
 		},
 	}
-			for _, tc := range tests {
-				got := inferSeriesNameFromPath(tc.path)
-				if got != tc.want {
-					t.Errorf("inferSeriesNameFromPath(%q) = %q, want %q", tc.path, got, tc.want)
-				}
-			}
+	for _, tc := range tests {
+		got := inferSeriesNameFromPath(tc.path)
+		if got != tc.want {
+			t.Errorf("inferSeriesNameFromPath(%q) = %q, want %q", tc.path, got, tc.want)
 		}
+	}
+}
 
 func TestEmbySeriesSortByDateLastMediaAdded(t *testing.T) {
 	svc := newTestEmbyService(t)

internal/service/emby_series_payload.go

@@ -5,28 +5,28 @@ func (e *EmbyService) seriesPayload(group embySeriesGroup) map[string]any {
 	imageTags := map[string]string{}
 	backdropTags := []string{}
 	if group.PosterURL != "" {
-		imageTags["Primary"] = group.ID
+		imageTags["Primary"] = embyVirtualImageTag(group.ID, embyVirtualPrimaryTagSuffix)
 	}
-	if group.BackdropURL != "" {
-		backdropTags = append(backdropTags, group.ID+"-bd")
+	if group.BackdropURL != "" || group.PosterURL != "" {
+		backdropTags = append(backdropTags, embyVirtualImageTag(group.ID, embyVirtualBackdropTagSuffix))
 	}
-		lastMediaAdded := group.DateLastMediaAdded
-		if lastMediaAdded.IsZero() {
-			lastMediaAdded = group.CreatedAt
-		}
-		item := map[string]any{
-			"Id":                 group.ID,
-			"Name":               group.Name,
-			"ServerId":           embyServerID,
-			"Type":               "Series",
-			"MediaType":          "Video",
-			"IsFolder":           true,
-			"ParentId":           group.LibraryID,
-			"ProductionYear":     group.Year,
-			"Overview":           group.Overview,
-			"CommunityRating":    group.Rating,
-			"RecursiveItemCount": len(group.Episodes),
-			"ChildCount":         len(e.seasonsForSeries(group)),
+	lastMediaAdded := group.DateLastMediaAdded
+	if lastMediaAdded.IsZero() {
+		lastMediaAdded = group.CreatedAt
+	}
+	item := map[string]any{
+		"Id":                 group.ID,
+		"Name":               group.Name,
+		"ServerId":           embyServerID,
+		"Type":               "Series",
+		"MediaType":          "Video",
+		"IsFolder":           true,
+		"ParentId":           group.LibraryID,
+		"ProductionYear":     group.Year,
+		"Overview":           group.Overview,
+		"CommunityRating":    group.Rating,
+		"RecursiveItemCount": len(group.Episodes),
+		"ChildCount":         len(e.seasonsForSeries(group)),
 		"DateCreated":        group.CreatedAt,
 		"DateLastMediaAdded": lastMediaAdded,
 		"ImageTags":          imageTags,
@@ -39,7 +39,7 @@ func (e *EmbyService) seriesPayload(group embySeriesGroup) map[string]any {
 		"UserData": emptyUserData(),
 	}
 	if group.PosterURL != "" {
-		item["PrimaryImageTag"] = group.ID
+		item["PrimaryImageTag"] = embyVirtualImageTag(group.ID, embyVirtualPrimaryTagSuffix)
 	}
 	if premiered, ok := embyPremiereDate(group.ReleaseDate); ok {
 		item["PremiereDate"] = premiered
@@ -52,10 +52,10 @@ func (e *EmbyService) seasonPayload(season embySeasonGroup) map[string]any {
 	imageTags := map[string]string{}
 	backdropTags := []string{}
 	if season.Series.PosterURL != "" {
-		imageTags["Primary"] = season.ID
+		imageTags["Primary"] = embyVirtualImageTag(season.ID, embyVirtualPrimaryTagSuffix)
 	}
-	if season.Series.BackdropURL != "" {
-		backdropTags = append(backdropTags, season.ID+"-bd")
+	if season.Series.BackdropURL != "" || season.Series.PosterURL != "" {
+		backdropTags = append(backdropTags, embyVirtualImageTag(season.ID, embyVirtualBackdropTagSuffix))
 	}
 	item := map[string]any{
 		"Id":                season.ID,
@@ -75,12 +75,12 @@ func (e *EmbyService) seasonPayload(season embySeasonGroup) map[string]any {
 		"UserData":          emptyUserData(),
 	}
 	if season.Series.PosterURL != "" {
-		item["PrimaryImageTag"] = season.ID
-		item["SeriesPrimaryImageTag"] = season.Series.ID
+		item["PrimaryImageTag"] = embyVirtualImageTag(season.ID, embyVirtualPrimaryTagSuffix)
+		item["SeriesPrimaryImageTag"] = embyVirtualImageTag(season.Series.ID, embyVirtualPrimaryTagSuffix)
 	}
-	if season.Series.BackdropURL != "" {
+	if season.Series.BackdropURL != "" || season.Series.PosterURL != "" {
 		item["ParentBackdropItemId"] = season.Series.ID
-		item["ParentBackdropImageTags"] = []string{season.Series.ID + "-bd"}
+		item["ParentBackdropImageTags"] = []string{embyVirtualImageTag(season.Series.ID, embyVirtualBackdropTagSuffix)}
 	}
 	return item
 }

internal/service/image_proxy_remote.go

@@ -55,26 +55,32 @@ func (p *ImageProxy) RemoveFailed(raw string) error {
 // Serve writes the requested image to w. Caller is expected to validate
 // the JWT before invoking it.
 func (p *ImageProxy) Serve(ctx context.Context, w http.ResponseWriter, r *http.Request, raw string) error {
+	// Emby 客户端用 maxWidth / maxHeight / quality 请求缩略图。不解析这些
+	// 参数就会把多兆字节的原图发给客户端，移动端往往在下载中途超时。
+	opts := parseImageResizeOptions(r)
 	if isLocalImagePath(raw) {
-		return p.serveLocalImage(w, r, raw)
+		return p.serveLocalImage(w, r, raw, opts)
 	}
-	return p.serveRemoteImage(ctx, w, r, raw)
+	return p.serveRemoteImage(ctx, w, r, raw, opts)
 }
 
-func (p *ImageProxy) serveLocalImage(w http.ResponseWriter, r *http.Request, raw string) error {
+func (p *ImageProxy) serveLocalImage(w http.ResponseWriter, r *http.Request, raw string, opts imageResizeOptions) error {
 	path := filepath.Clean(raw)
 	abs, err := filepath.Abs(path)
 	if err != nil || !p.isAllowedLocalPath(abs) {
 		servePlaceholder(w)
 		return nil
 	}
+	if opts.active() && p.serveResizedFromFile(w, r, abs, opts) {
+		return nil
+	}
 	if !serveImageFile(w, r, filepath.Base(abs), abs, imageBrowserCacheControl) {
 		servePlaceholder(w)
 	}
 	return nil
 }
 
-func (p *ImageProxy) serveRemoteImage(ctx context.Context, w http.ResponseWriter, r *http.Request, raw string) error {
+func (p *ImageProxy) serveRemoteImage(ctx context.Context, w http.ResponseWriter, r *http.Request, raw string, opts imageResizeOptions) error {
 	u, err := p.validateURL(raw)
 	if err != nil {
 		return err
@@ -83,14 +89,14 @@ func (p *ImageProxy) serveRemoteImage(ctx context.Context, w http.ResponseWriter
 	key, cachePath, failPath := p.remoteImageCachePathsForValidated(raw)
 	forceRefresh := r.URL.Query().Get("refresh") != ""
 	p.removeUnusableImageCache(cachePath, failPath)
-	if !forceRefresh && serveCachedImageFile(w, r, key, cachePath) {
+	if !forceRefresh && p.serveCachedImage(w, r, key, cachePath, opts) {
 		return nil
 	}
 	// No negative caching: a previously failed fetch is retried on every
 	// subsequent request, so the image recovers as soon as upstream does.
 	data, ctype, contentLength, err := p.fetchAndCacheRemoteImage(ctx, raw, host, cachePath, failPath)
 	if err != nil {
-		if forceRefresh && serveCachedImageFile(w, r, key, cachePath) {
+		if forceRefresh && p.serveCachedImage(w, r, key, cachePath, opts) {
 			return nil
 		}
 		if errors.Is(err, errImageProxyRequestSetup) {
@@ -100,6 +106,10 @@ func (p *ImageProxy) serveRemoteImage(ctx context.Context, w http.ResponseWriter
 		}
 		return nil
 	}
+	// 上游原图已落盘，缩放结果复用同一条缓存流水线。
+	if opts.active() && p.serveResizedFromFile(w, r, cachePath, opts) {
+		return nil
+	}
 	w.Header().Set("Content-Type", ctype)
 	if contentLength != "" {
 		w.Header().Set("Content-Length", contentLength)
@@ -114,6 +124,15 @@ func (p *ImageProxy) serveRemoteImage(ctx context.Context, w http.ResponseWriter
 	return nil
 }
 
+// serveCachedImage 在远程原图已缓存时提供服务。请求带缩放参数时优先命中
+// 缩放缓存，未命中则从已缓存的原图生成一份；缩放不可用时退回原图直出。
+func (p *ImageProxy) serveCachedImage(w http.ResponseWriter, r *http.Request, key, cachePath string, opts imageResizeOptions) bool {
+	if opts.active() && p.serveResizedFromFile(w, r, cachePath, opts) {
+		return true
+	}
+	return serveCachedImageFile(w, r, key, cachePath)
+}
+
 func (p *ImageProxy) removeUnusableImageCache(cachePath, failPath string) {
 	data, err := os.ReadFile(cachePath) // #nosec G304 -- cachePath is SHA-derived under cacheDir.
 	if err != nil {

internal/service/image_resize.go

@@ -0,0 +1,269 @@
+package service
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"image"
+	"image/jpeg"
+	"image/png"
+	"math"
+	"net/http"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"go.uber.org/zap"
+
+	_ "golang.org/x/image/bmp" // register BMP decoder for .bmp/.tbn sidecar art
+	"golang.org/x/image/draw"
+	_ "golang.org/x/image/webp" // register WebP decoder for poster art
+)
+
+const (
+	imageResizeDefaultQuality = 90
+	imageResizeMinQuality     = 1
+	imageResizeMaxQuality     = 100
+
+	// imageResizeMaxSourcePixels 限制参与缩放的原图像素总量。解码一张
+	// N 像素的图在内存中约需 4N 字节；没有上限时，一张异常的超大图
+	// 就能在多张并发缩略图请求下打爆小内存主机。超过该上限时直接
+	// 回退为原图直出，宁可不缩放也不冒 OOM 风险。
+	imageResizeMaxSourcePixels = 30_000_000
+
+	// imageResizeCacheSubdir 存放缩放结果，与远程原图缓存分开放，
+	// 便于单独清理且不与原始字节流缓存互相覆盖。
+	imageResizeCacheSubdir = "resized"
+)
+
+// imageResizeOptions 描述客户端通过图片 URL 查询参数请求的目标尺寸。
+// Emby / Infuse / Yamby / RodelPlayer 等客户端普遍使用
+// maxWidth / maxHeight / quality，也有客户端使用 width / height。
+type imageResizeOptions struct {
+	MaxWidth  int
+	MaxHeight int
+	Quality   int
+}
+
+// active 报告是否需要缩放。没有任何尺寸参数时返回 false，调用方保持
+// 原有的原图直出路径（支持 Range / ETag，行为完全不变）。
+func (o imageResizeOptions) active() bool {
+	return o.MaxWidth > 0 || o.MaxHeight > 0
+}
+
+// encodingQuality 返回生效的 JPEG 编码质量，缺省 90。
+func (o imageResizeOptions) encodingQuality() int {
+	q := o.Quality
+	if q < imageResizeMinQuality || q > imageResizeMaxQuality {
+		return imageResizeDefaultQuality
+	}
+	return q
+}
+
+// parseImageResizeOptions 从请求查询串解析缩放参数。Emby 客户端对参数名
+// 大小写不敏感，这里逐项做 EqualFold 匹配。
+func parseImageResizeOptions(r *http.Request) imageResizeOptions {
+	if r == nil || r.URL == nil {
+		return imageResizeOptions{}
+	}
+	q := r.URL.Query()
+	return imageResizeOptions{
+		MaxWidth:  firstPositiveQueryInt(q, "maxWidth", "width"),
+		MaxHeight: firstPositiveQueryInt(q, "maxHeight", "height"),
+		Quality:   firstPositiveQueryInt(q, "quality"),
+	}
+}
+
+// firstPositiveQueryInt 按顺序返回第一个能解析为正数的查询参数。
+func firstPositiveQueryInt(q url.Values, names ...string) int {
+	for _, name := range names {
+		for key, values := range q {
+			if !strings.EqualFold(key, name) {
+				continue
+			}
+			for _, raw := range values {
+				raw = strings.TrimSpace(raw)
+				if n, err := strconv.Atoi(raw); err == nil && n > 0 {
+					return n
+				}
+				// Emby 客户端偶发传入 "400.0" 这类浮点字面量。
+				if f, err := strconv.ParseFloat(raw, 64); err == nil && f > 0 {
+					return int(f)
+				}
+			}
+		}
+	}
+	return 0
+}
+
+// fitSize 按等比缩放把 srcW x srcH 装进 maxW/maxH 边界，且从不放大。
+func fitSize(srcW, srcH, maxW, maxH int) (int, int) {
+	if srcW <= 0 || srcH <= 0 {
+		return srcW, srcH
+	}
+	scale := 1.0
+	if maxW > 0 && srcW > maxW {
+		scale = math.Min(scale, float64(maxW)/float64(srcW))
+	}
+	if maxH > 0 && srcH > maxH {
+		scale = math.Min(scale, float64(maxH)/float64(srcH))
+	}
+	if scale >= 1 {
+		return srcW, srcH
+	}
+	dstW := int(math.Round(float64(srcW) * scale))
+	dstH := int(math.Round(float64(srcH) * scale))
+	if dstW < 1 {
+		dstW = 1
+	}
+	if dstH < 1 {
+		dstH = 1
+	}
+	return dstW, dstH
+}
+
+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）。
+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
+	}
+	cfg, format, err := image.DecodeConfig(bytes.NewReader(data))
+	if err != nil {
+		return nil, "", false, err
+	}
+	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。
+	dstW, dstH := fitSize(cfg.Width, cfg.Height, o.MaxWidth, o.MaxHeight)
+	if dstW == cfg.Width && dstH == cfg.Height {
+		return data, detectContentType(data), true, nil
+	}
+	if int64(cfg.Width)*int64(cfg.Height) > imageResizeMaxSourcePixels {
+		return nil, "", false, errImageResizeTooLarge
+	}
+
+	src, _, err := image.Decode(bytes.NewReader(data))
+	if err != nil {
+		return nil, "", false, err
+	}
+	dst := image.NewRGBA(image.Rect(0, 0, dstW, dstH))
+	draw.CatmullRom.Scale(dst, dst.Bounds(), src, src.Bounds(), draw.Src, nil)
+
+	// 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
+	// 像素后统一转 JPEG —— 客户端本来就只按缩略图显示。
+	if strings.EqualFold(format, "png") && !isOpaqueImage(dst) {
+		var buf bytes.Buffer
+		if err := png.Encode(&buf, dst); err != nil {
+			return nil, "", false, err
+		}
+		return buf.Bytes(), "image/png", false, nil
+	}
+
+	var buf bytes.Buffer
+	if err := jpeg.Encode(&buf, dst, &jpeg.Options{Quality: o.encodingQuality()}); err != nil {
+		return nil, "", false, err
+	}
+	return buf.Bytes(), "image/jpeg", false, nil
+}
+
+// isOpaqueImage 逐像素确认图像不含透明像素。
+func isOpaqueImage(img *image.RGBA) bool {
+	bounds := img.Bounds()
+	for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
+		for x := bounds.Min.X; x < bounds.Max.X; x++ {
+			if _, _, _, a := img.At(x, y).RGBA(); a != 0xffff {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// resizeCacheKey 生成缩放结果的缓存键，覆盖源文件身份（路径 + 大小 +
+// 修改时间）与全部影响输出的参数，源文件被替换后不会命中陈旧缩略图。
+func (o imageResizeOptions) resizeCacheKey(sourceID string, stat os.FileInfo) string {
+	h := sha256.New()
+	_, _ = fmt.Fprintf(h, "v1|%s|%dx%d|q%d", sourceID, o.MaxWidth, o.MaxHeight, o.encodingQuality())
+	if stat != nil {
+		_, _ = fmt.Fprintf(h, "|%d|%d", stat.Size(), stat.ModTime().UnixNano())
+	}
+	return hex.EncodeToString(h.Sum(nil))
+}
+
+func (p *ImageProxy) resizeCachePath(key string) string {
+	return filepath.Join(p.cacheDir, imageResizeCacheSubdir, key+".img")
+}
+
+// serveResizedFromFile 从 srcPath 读取图片，按选项缩放后写出，并把结果缓存
+// 到磁盘以免每次请求都重新解码。原图已满足目标尺寸时直接输出原文件。
+// 返回 false 表示缩放不可用，调用方应回退到原图直出。
+func (p *ImageProxy) serveResizedFromFile(w http.ResponseWriter, r *http.Request, srcPath string, o imageResizeOptions) bool {
+	stat, err := os.Stat(srcPath)
+	if err != nil || stat.IsDir() || stat.Size() <= 0 {
+		return false
+	}
+	data, err := os.ReadFile(srcPath) // #nosec G304 -- srcPath comes from an allowed local path or a SHA-derived cache path.
+	if err != nil {
+		return false
+	}
+	out, ctype, unchanged, err := resizeImageData(data, o)
+	if err != nil {
+		return false
+	}
+	if unchanged {
+		// 原图已经在目标尺寸内：直接流式输出，保留 ETag / Range 语义。
+		return serveImageFile(w, r, filepath.Base(srcPath), srcPath, imageBrowserCacheControl)
+	}
+
+	key := o.resizeCacheKey(srcPath, stat)
+	cachePath := p.resizeCachePath(key)
+	if serveCachedImageFile(w, r, key, cachePath) {
+		return true
+	}
+	p.writeResizeCache(cachePath, out)
+	w.Header().Set("Content-Type", ctype)
+	w.Header().Set("Cache-Control", imageBrowserCacheControl)
+	http.ServeContent(w, r, key, stat.ModTime(), bytes.NewReader(out))
+	return true
+}
+
+// writeResizeCache 原子写入缩放结果；失败只记日志，不影响本次响应。
+func (p *ImageProxy) writeResizeCache(cachePath string, data []byte) {
+	dir := filepath.Dir(cachePath)
+	if err := os.MkdirAll(dir, 0o750); err != nil {
+		p.warn("imageproxy: resize cache mkdir failed", err)
+		return
+	}
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	tmp, err := os.CreateTemp(dir, "resized-*.tmp")
+	if err != nil {
+		p.warn("imageproxy: resize cache temp failed", err)
+		return
+	}
+	if _, err := tmp.Write(data); err != nil {
+		_ = tmp.Close()
+		_ = os.Remove(tmp.Name())
+		return
+	}
+	_ = tmp.Close()
+	if err := os.Rename(tmp.Name(), cachePath); err != nil {
+		_ = os.Remove(tmp.Name())
+	}
+}
+
+func (p *ImageProxy) warn(msg string, err error) {
+	if p == nil || p.log == nil {
+		return
+	}
+	p.log.Warn(msg, zap.Error(err))
+}

internal/service/image_resize_test.go

@@ -0,0 +1,232 @@
+package service
+
+import (
+	"bytes"
+	"image"
+	"image/color"
+	"image/png"
+	"net/http/httptest"
+	"os"
+	"testing"
+)
+
+// encodeTestPNG 生成一张结构规则、易于压缩的测试用 PNG。
+func encodeTestPNG(t *testing.T, w, h int, alpha uint8) []byte {
+	t.Helper()
+	img := image.NewRGBA(image.Rect(0, 0, w, h))
+	for y := 0; y < h; y++ {
+		for x := 0; x < w; x++ {
+			img.Set(x, y, color.RGBA{R: uint8(x % 16 * 16), G: uint8(y % 16 * 16), B: 200, A: alpha})
+		}
+	}
+	var buf bytes.Buffer
+	if err := png.Encode(&buf, img); err != nil {
+		t.Fatalf("encode test png: %v", err)
+	}
+	return buf.Bytes()
+}
+
+func TestParseImageResizeOptionsReadsEmbyParams(t *testing.T) {
+	r := httptest.NewRequest("GET", "/emby/Items/x/Images/Primary?maxWidth=400&maxHeight=600&quality=80", nil)
+	o := parseImageResizeOptions(r)
+	if o.MaxWidth != 400 || o.MaxHeight != 600 || o.Quality != 80 {
+		t.Fatalf("unexpected options: %+v", o)
+	}
+	if !o.active() {
+		t.Fatal("expected options to be active")
+	}
+}
+
+func TestParseImageResizeOptionsIsCaseInsensitive(t *testing.T) {
+	r := httptest.NewRequest("GET", "/x?MaxWidth=250&QUALITY=70", nil)
+	o := parseImageResizeOptions(r)
+	if o.MaxWidth != 250 {
+		t.Fatalf("MaxWidth = %d, want 250", o.MaxWidth)
+	}
+	if o.Quality != 70 {
+		t.Fatalf("Quality = %d, want 70", o.Quality)
+	}
+}
+
+func TestParseImageResizeOptionsAcceptsWidthAndHeightAliases(t *testing.T) {
+	r := httptest.NewRequest("GET", "/x?width=320&height=180", nil)
+	o := parseImageResizeOptions(r)
+	if o.MaxWidth != 320 || o.MaxHeight != 180 {
+		t.Fatalf("unexpected options: %+v", o)
+	}
+}
+
+func TestParseImageResizeOptionsInactiveWithoutDimensions(t *testing.T) {
+	r := httptest.NewRequest("GET", "/x?quality=90&tag=abc", nil)
+	o := parseImageResizeOptions(r)
+	if o.active() {
+		t.Fatalf("expected inactive options, got %+v", o)
+	}
+}
+
+func TestFitSizePreservesAspectAndNeverUpscales(t *testing.T) {
+	cases := []struct {
+		name                   string
+		srcW, srcH, maxW, maxH int
+		wantW, wantH           int
+	}{
+		{"max-width-only", 529, 911, 400, 0, 400, 689},
+		{"max-height-only", 529, 911, 0, 500, 290, 500},
+		{"never-upscales", 529, 911, 2000, 2000, 529, 911},
+		{"both-bounds", 1000, 500, 400, 400, 400, 200},
+		{"exact-size", 400, 600, 400, 600, 400, 600},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			gotW, gotH := fitSize(tc.srcW, tc.srcH, tc.maxW, tc.maxH)
+			if gotW != tc.wantW || gotH != tc.wantH {
+				t.Fatalf("fitSize(%d,%d,%d,%d) = %dx%d, want %dx%d",
+					tc.srcW, tc.srcH, tc.maxW, tc.maxH, gotW, gotH, tc.wantW, tc.wantH)
+			}
+		})
+	}
+}
+
+func TestResizeImageDataScalesDownAndReencodesAsJPEG(t *testing.T) {
+	data := encodeTestPNG(t, 529, 911, 255)
+	out, ctype, unchanged, err := resizeImageData(data, imageResizeOptions{MaxWidth: 400, Quality: 90})
+	if err != nil {
+		t.Fatalf("resize: %v", err)
+	}
+	if unchanged {
+		t.Fatal("expected the image to be resized")
+	}
+	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 resized: %v", err)
+	}
+	if cfg.Width != 400 || cfg.Height != 689 {
+		t.Fatalf("resized to %dx%d, want 400x689", cfg.Width, cfg.Height)
+	}
+	if format != "jpeg" {
+		t.Fatalf("format = %q, want jpeg", format)
+	}
+	// 这里只断言"重新编码生效且输出可解码"。合成图的压缩率不代表真实海报
+	// （规则色块 PNG 极小，而 JPEG 压规则图案反而更大）；真实海报的体积
+	// 收益在服务器上用线上素材实测。
+	if len(out) == 0 {
+		t.Fatal("expected a non-empty resized image")
+	}
+	if len(out) == len(data) {
+		t.Fatal("expected the resized image to be re-encoded")
+	}
+}
+
+func TestResizeImageDataLeavesImagesWithinBoundsUntouched(t *testing.T) {
+	data := encodeTestPNG(t, 200, 300, 255)
+	out, _, 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")
+	}
+	if !bytes.Equal(out, data) {
+		t.Fatal("expected the original bytes to be returned verbatim")
+	}
+}
+
+func TestResizeImageDataKeepsTransparencyAsPNG(t *testing.T) {
+	data := encodeTestPNG(t, 600, 900, 128)
+	out, ctype, unchanged, err := resizeImageData(data, imageResizeOptions{MaxWidth: 300, Quality: 90})
+	if err != nil {
+		t.Fatalf("resize: %v", err)
+	}
+	if unchanged {
+		t.Fatal("expected the image to be resized")
+	}
+	if ctype != "image/png" {
+		t.Fatalf("content type = %q, want image/png so transparency is preserved", ctype)
+	}
+	cfg, format, err := image.DecodeConfig(bytes.NewReader(out))
+	if err != nil {
+		t.Fatalf("decode resized: %v", err)
+	}
+	if format != "png" {
+		t.Fatalf("format = %q, want png", format)
+	}
+	if cfg.Width != 300 || cfg.Height != 450 {
+		t.Fatalf("resized to %dx%d, want 300x450", cfg.Width, cfg.Height)
+	}
+}
+
+func TestImageResizeOptionsCacheKeyVariesWithParametersAndSource(t *testing.T) {
+	stat, err := os.Stat("image_resize_test.go")
+	if err != nil {
+		t.Fatalf("stat: %v", err)
+	}
+	base := imageResizeOptions{MaxWidth: 400, Quality: 90}
+	if base.resizeCacheKey("a", stat) != base.resizeCacheKey("a", stat) {
+		t.Fatal("cache key must be stable for identical inputs")
+	}
+	if base.resizeCacheKey("a", stat) == base.resizeCacheKey("b", stat) {
+		t.Fatal("cache key must differ between sources")
+	}
+	if base.resizeCacheKey("a", stat) == (imageResizeOptions{MaxWidth: 200, Quality: 90}).resizeCacheKey("a", stat) {
+		t.Fatal("cache key must differ when max width changes")
+	}
+	if base.resizeCacheKey("a", stat) == (imageResizeOptions{MaxWidth: 400, Quality: 60}).resizeCacheKey("a", stat) {
+		t.Fatal("cache key must differ when quality changes")
+	}
+}
+
+func TestImageResizeOptionsEncodingQualityFallsBackToDefault(t *testing.T) {
+	for _, tc := range []struct {
+		in   int
+		want int
+	}{
+		{0, imageResizeDefaultQuality},
+		{-5, imageResizeDefaultQuality},
+		{500, imageResizeDefaultQuality},
+		{1, 1},
+		{100, 100},
+		{75, 75},
+	} {
+		if got := (imageResizeOptions{Quality: tc.in}).encodingQuality(); got != tc.want {
+			t.Fatalf("encodingQuality(%d) = %d, want %d", tc.in, got, tc.want)
+		}
+	}
+}
+
+func TestServeResizedFromFileCachesScaledResult(t *testing.T) {
+	dir := t.TempDir()
+	mediaDir := dir + string(os.PathSeparator) + "media"
+	if err := os.MkdirAll(mediaDir, 0o755); err != nil {
+		t.Fatalf("mkdir: %v", err)
+	}
+	src := mediaDir + string(os.PathSeparator) + "poster.png"
+	if err := os.WriteFile(src, encodeTestPNG(t, 529, 911, 255), 0o644); err != nil {
+		t.Fatalf("write source: %v", err)
+	}
+
+	proxy := &ImageProxy{cacheDir: dir + string(os.PathSeparator) + "cache"}
+	opts := imageResizeOptions{MaxWidth: 400, Quality: 90}
+
+	first := httptest.NewRecorder()
+	if !proxy.serveResizedFromFile(first, httptest.NewRequest("GET", "/x?maxWidth=400", nil), src, opts) {
+		t.Fatal("expected serveResizedFromFile to handle the request")
+	}
+	if got := first.Header().Get("Content-Type"); got != "image/jpeg" {
+		t.Fatalf("content type = %q, want image/jpeg", got)
+	}
+
+	// 第二次请求应命中磁盘缓存，返回与首次完全相同的字节。
+	second := httptest.NewRecorder()
+	if !proxy.serveResizedFromFile(second, httptest.NewRequest("GET", "/x?maxWidth=400", nil), src, opts) {
+		t.Fatal("expected second call to be served")
+	}
+	if !bytes.Equal(first.Body.Bytes(), second.Body.Bytes()) {
+		t.Fatal("expected the cached scaled image to be reused")
+	}
+	if len(first.Body.Bytes()) == 0 {
+		t.Fatal("expected a non-empty body")
+	}
+}

internal/service/local_metadata_artwork.go

@@ -158,7 +158,7 @@ func firstExistingImage(dir string, names ...string) string {
 		return ""
 	}
 	for _, name := range names {
-		for _, ext := range []string{".jpg", ".jpeg", ".png", ".webp", ".gif", ".bmp", ".tbn"} {
+		for _, ext := range []string{".jpg", ".jpeg", ".png", ".webp", ".gif", ".bmp", ".tbn", ".img"} {
 			path := filepath.Join(dir, name+ext)
 			if fileExists(path) {
 				return filepath.Clean(path)
@@ -221,7 +221,7 @@ func firstExistingPosterImage(dir string, names ...string) string {
 		if isRejectedPosterName(name) {
 			continue
 		}
-		for _, ext := range []string{".jpg", ".jpeg", ".png", ".webp", ".gif", ".bmp", ".tbn"} {
+		for _, ext := range []string{".jpg", ".jpeg", ".png", ".webp", ".gif", ".bmp", ".tbn", ".img"} {
 			path := filepath.Join(dir, name+ext)
 			if fileExists(path) && likelyPosterImage(path) {
 				return filepath.Clean(path)
@@ -240,7 +240,7 @@ func firstAdultLooseImage(dir, kind string) string {
 	fallback := []string{}
 	for _, path := range matches {
 		ext := strings.ToLower(filepath.Ext(path))
-		if ext != ".jpg" && ext != ".jpeg" && ext != ".png" && ext != ".webp" && ext != ".gif" && ext != ".bmp" && ext != ".tbn" {
+		if ext != ".jpg" && ext != ".jpeg" && ext != ".png" && ext != ".webp" && ext != ".gif" && ext != ".bmp" && ext != ".tbn" && ext != ".img" {
 			continue
 		}
 		name := strings.ToLower(strings.TrimSuffix(filepath.Base(path), ext))

internal/service/local_metadata_test.go

@@ -417,3 +417,22 @@ func TestReadLocalMetadataArtworkFallbackOnGarbageShowNFO(t *testing.T) {
 		t.Fatalf("expected episode artwork fallback, got %+v", got)
 	}
 }
+
+func TestReadLocalMetadataFindsLegacyImgPoster(t *testing.T) {
+	root := t.TempDir()
+	mediaPath := filepath.Join(root, "Jigokuraku.S01E14.mkv.strm")
+	poster := filepath.Join(root, "Jigokuraku.S01E14-poster.img")
+	if err := os.WriteFile(mediaPath, []byte("https://example.test/video"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(poster, testJPEG, 0o644); err != nil {
+		t.Fatal(err)
+	}
+	got, err := ReadLocalMetadata(mediaPath, root, true)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got == nil || got.PosterURL != poster {
+		t.Fatalf("PosterURL = %q, want legacy .img poster %q", got.PosterURL, poster)
+	}
+}

internal/service/media_path_alias.go

@@ -0,0 +1,101 @@
+package service
+
+import (
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+)
+
+// strmPathAliases returns sibling STRM names that can represent the same media
+// item when keep_ext is toggled on or off.
+//
+// Both directions are supported:
+//
+//	foo.strm      <-> foo.mkv.strm
+//	foo.strm      <-> foo.mp4.strm
+//
+// The caller must still verify that the aliases are no longer present on disk.
+// keep_ext intentionally allows foo.mkv.strm and foo.mp4.strm to coexist as
+// two real versions, so an existing sibling must never be absorbed.
+func strmPathAliases(path string) []string {
+	clean := filepath.Clean(strings.TrimSpace(path))
+	if clean == "" || clean == "." || !strings.EqualFold(filepath.Ext(clean), ".strm") {
+		return nil
+	}
+	base := mediaSidecarBase(clean)
+	if base == "" {
+		return nil
+	}
+	name := filepath.Base(clean)
+	stem := strings.TrimSuffix(name, filepath.Ext(name))
+	lastExt := strings.ToLower(filepath.Ext(stem))
+	_, hasVideoExt := videoExtensions[lastExt]
+	hasVideoExt = hasVideoExt && !strings.EqualFold(lastExt, ".strm")
+
+	dir := filepath.Dir(clean)
+	out := make([]string, 0, len(videoExtensions)+1)
+	seen := make(map[string]struct{}, len(videoExtensions)+1)
+	add := func(candidate string) {
+		candidate = filepath.Clean(candidate)
+		if candidate == "" || candidate == "." || samePath(candidate, clean) {
+			return
+		}
+		key := strings.ToLower(candidate)
+		if _, ok := seen[key]; ok {
+			return
+		}
+		seen[key] = struct{}{}
+		out = append(out, candidate)
+	}
+	if hasVideoExt {
+		// Current keep_ext shape: the only legacy shape is the stripped name.
+		add(filepath.Join(dir, base+".strm"))
+		return out
+	}
+	// Stripped shape: an old keep_ext file may use any configured video ext.
+	exts := make([]string, 0, len(videoExtensions))
+	for ext := range videoExtensions {
+		if strings.EqualFold(ext, ".strm") {
+			continue
+		}
+		exts = append(exts, strings.ToLower(ext))
+	}
+	sort.Strings(exts)
+	for _, ext := range exts {
+		add(filepath.Join(dir, base+ext+".strm"))
+		if upper := strings.ToUpper(ext); upper != ext {
+			add(filepath.Join(dir, base+upper+".strm"))
+		}
+	}
+	return out
+}
+
+// missingSTRMPathAliases keeps only aliases which no longer exist on disk.
+// This is the key protection for keep_ext=true multi-version libraries: an
+// existing foo.mp4.strm is a real second version, not a rename tombstone.
+func missingSTRMPathAliases(path string) []string {
+	aliases := strmPathAliases(path)
+	if len(aliases) == 0 {
+		return nil
+	}
+	out := make([]string, 0, len(aliases))
+	for _, alias := range aliases {
+		if _, err := os.Lstat(alias); err == nil {
+			continue
+		} else if !os.IsNotExist(err) {
+			continue
+		}
+		out = append(out, alias)
+	}
+	return out
+}
+
+func liveSTRMPathAlias(path string) bool {
+	for _, alias := range strmPathAliases(path) {
+		if info, err := os.Stat(alias); err == nil && !info.IsDir() {
+			return true
+		}
+	}
+	return false
+}

internal/service/media_series.go

@@ -301,16 +301,8 @@ func groupMediaSeriesCards(items []model.Media) []SeriesCard {
 			if betterSeriesLinkMedia(item, card.LinkMedia) {
 				card.LinkMedia = item
 			}
-			currentArtwork := seriesArtworkScore(item)
-			representativeArtwork := seriesArtworkScore(card.Rep)
-			if currentArtwork > representativeArtwork {
+			if betterSeriesRepresentative(item, card.Rep) {
 				card.Rep = item
-			} else if currentArtwork == representativeArtwork {
-				cur := item.SeasonNum*10000 + item.EpisodeNum
-				rep := card.Rep.SeasonNum*10000 + card.Rep.EpisodeNum
-				if cur > 0 && (rep == 0 || cur < rep) {
-					card.Rep = item
-				}
 			}
 			continue
 		}
@@ -335,6 +327,27 @@ func groupMediaSeriesCards(items []model.Media) []SeriesCard {
 	return cards
 }
 
+func betterSeriesRepresentative(candidate, current model.Media) bool {
+	// A theatrical feature can have local poster.jpg/background.jpg files and
+	// therefore a higher artwork score than its TV episodes. Keep the TV row as
+	// the visible identity of a mixed series card so a movie cannot hijack the
+	// series title, overview, and artwork.
+	candidateTheatrical := mediaLooksLikeTheatricalFeature(&candidate)
+	currentTheatrical := mediaLooksLikeTheatricalFeature(&current)
+	if candidateTheatrical != currentTheatrical {
+		return !candidateTheatrical
+	}
+
+	currentArtwork := seriesArtworkScore(candidate)
+	representativeArtwork := seriesArtworkScore(current)
+	if currentArtwork != representativeArtwork {
+		return currentArtwork > representativeArtwork
+	}
+	cur := candidate.SeasonNum*10000 + candidate.EpisodeNum
+	rep := current.SeasonNum*10000 + current.EpisodeNum
+	return cur > 0 && (rep == 0 || cur < rep)
+}
+
 func seriesMediaTime(media model.Media) time.Time {
 	if releaseDate := strings.TrimSpace(media.ReleaseDate); releaseDate != "" {
 		if parsed, err := time.Parse("2006-01-02", releaseDate); err == nil {

internal/service/media_series_resolver.go

@@ -67,17 +67,20 @@ func newMediaSeriesKeyResolver(items []model.Media) mediaSeriesKeyResolver {
 
 func (r mediaSeriesKeyResolver) key(media model.Media) string {
 	if mediaLooksEpisodicForGrouping(media) {
-		if key := repeatedSeriesTitleKey(media); key != "" && r.titleCounts[key] > 1 {
-			return compactSeriesKey(key)
-		}
 		if pathKey := mediaSeriesRawKey(media); strings.HasPrefix(pathKey, "library-path") {
 			if titleKey := r.pathTitles[pathKey]; titleKey != "" {
 				return compactSeriesKey(titleKey)
 			}
+			// A series directory is the strongest identity for mixed rows:
+			// main episodes and specials (CM/NCOP/PV/OVA) may be scraped to
+			// slightly different titles, but they still belong to one show.
 			if r.pathCounts[pathKey] > 1 {
 				return compactSeriesKey(pathKey)
 			}
 		}
+		if key := repeatedSeriesTitleKey(media); key != "" && r.titleCounts[key] > 1 {
+			return compactSeriesKey(key)
+		}
 		if key := repeatedSeriesExternalKey(media); key != "" && r.externalCounts[key] > 1 {
 			return compactSeriesKey(key)
 		}

internal/service/media_series_test.go

@@ -47,14 +47,14 @@ func TestListRecentSeriesCardsCountsAllEpisodesInSeries(t *testing.T) {
 	if len(cards) != 1 {
 		t.Fatalf("recent cards = %#v, want one series card", cards)
 	}
-		if cards[0].Count != 40 {
-			t.Fatalf("recent series count = %d, want full 40 episodes", cards[0].Count)
-		}
-		expectedLastAdded := now.Add(40 * time.Minute)
-		if cards[0].LastAddedAt == nil || !cards[0].LastAddedAt.Equal(expectedLastAdded) {
-			t.Fatalf("recent series LastAddedAt = %v, want %v", cards[0].LastAddedAt, expectedLastAdded)
-		}
+	if cards[0].Count != 40 {
+		t.Fatalf("recent series count = %d, want full 40 episodes", cards[0].Count)
 	}
+	expectedLastAdded := now.Add(40 * time.Minute)
+	if cards[0].LastAddedAt == nil || !cards[0].LastAddedAt.Equal(expectedLastAdded) {
+		t.Fatalf("recent series LastAddedAt = %v, want %v", cards[0].LastAddedAt, expectedLastAdded)
+	}
+}
 
 func TestMediaSeriesKeyCollapsesNestedSpecialFolders(t *testing.T) {
 	main := model.Media{
@@ -377,6 +377,51 @@ func TestGroupMediaSeriesCardsMergesPollutedEpisodeFoldersBySharedShowID(t *test
 	}
 }
 
+func TestGroupMediaSeriesCardsKeepsMixedTitlesInSameEpisodicDirectoryTogether(t *testing.T) {
+	items := []model.Media{
+		{
+			Base:         model.Base{ID: "main-1"},
+			LibraryID:    "anime",
+			Title:        "住在拔作岛上的我应该如何是好？",
+			Path:         `/media/影视库/动漫/拔作岛/[64bitsub][Nukitashi][01][AVC_2×FLAC].mkv.strm`,
+			SeasonNum:    1,
+			EpisodeNum:   1,
+			ScrapeStatus: "matched",
+		},
+		{
+			Base:         model.Base{ID: "main-2"},
+			LibraryID:    "anime",
+			Title:        "住在拔作岛上的我应该如何是好？",
+			Path:         `/media/影视库/动漫/拔作岛/[64bitsub][Nukitashi][02][AVC_2×FLAC].mkv.strm`,
+			SeasonNum:    1,
+			EpisodeNum:   2,
+			ScrapeStatus: "matched",
+		},
+		{
+			Base:         model.Base{ID: "special-1"},
+			LibraryID:    "anime",
+			Title:        "nukitashi",
+			Path:         `/media/影视库/动漫/拔作岛/[64bitsub][Nukitashi][CM_01][AVC_FLAC].mkv.strm`,
+			ScrapeStatus: "matched",
+		},
+		{
+			Base:         model.Base{ID: "special-2"},
+			LibraryID:    "anime",
+			Title:        "nukitashi",
+			Path:         `/media/影视库/动漫/拔作岛/[64bitsub][Nukitashi][PV_01][AVC_FLAC].mkv.strm`,
+			ScrapeStatus: "matched",
+		},
+	}
+
+	cards := groupMediaSeriesCards(items)
+	if len(cards) != 1 {
+		t.Fatalf("cards=%#v, want main episodes and specials in the same directory folded into one card", cards)
+	}
+	if cards[0].Count != 4 {
+		t.Fatalf("series count=%d, want 4 items", cards[0].Count)
+	}
+}
+
 func TestGroupMediaSeriesCardsKeepsMovieVersionsAsOneMovie(t *testing.T) {
 	items := []model.Media{
 		{
@@ -410,15 +455,19 @@ func TestGroupMediaSeriesCardsKeepsTheatricalMovieWithTVSeries(t *testing.T) {
 		LibraryID:  "anime",
 		Title:      "摇曳露营△",
 		Path:       `/media/动漫/摇曳露营△ (2018)/Season 01/摇曳露营△.S01E01.mkv`,
+		PosterURL:  "https://image.tmdb.org/t/p/w500/episode.jpg",
 		SeasonNum:  1,
 		EpisodeNum: 1,
 	}
 	theatrical := model.Media{
-		Base:      model.Base{ID: "theatrical"},
-		LibraryID: "anime",
-		Title:     "摇曳露营△ 剧场版",
-		Path:      `/media/动漫/摇曳露营△ (2018)/摇曳露营△ 剧场版 (2022)/Eiga.Yurukyan.2022.Bluray.mkv`,
-		TMDbID:    566466,
+		Base:        model.Base{ID: "theatrical"},
+		LibraryID:   "anime",
+		Title:       "摇曳露营△ 剧场版",
+		Path:        `/media/动漫/摇曳露营△ (2018)/摇曳露营△ 剧场版 (2022)/Eiga.Yurukyan.2022.Bluray.mkv`,
+		PosterURL:   "/media/动漫/摇曳露营△ (2018)/剧场版/poster.jpg",
+		BackdropURL: "/media/动漫/摇曳露营△ (2018)/剧场版/background.jpg",
+		Overview:    "剧场版简介",
+		TMDbID:      566466,
 	}
 
 	cards := groupMediaSeriesCards([]model.Media{episode, theatrical})
@@ -428,6 +477,12 @@ func TestGroupMediaSeriesCardsKeepsTheatricalMovieWithTVSeries(t *testing.T) {
 	if cards[0].Count != 2 {
 		t.Fatalf("series card count=%d, want TV episode plus theatrical movie", cards[0].Count)
 	}
+	if cards[0].Rep.ID != episode.ID {
+		t.Fatalf("series representative=%q, want TV episode %q", cards[0].Rep.ID, episode.ID)
+	}
+	if cards[0].Rep.Title != episode.Title {
+		t.Fatalf("series representative title=%q, want %q", cards[0].Rep.Title, episode.Title)
+	}
 }
 
 func TestGroupMediaSeriesCardsDoesNotCollideMovieAndTVExternalIDs(t *testing.T) {
@@ -493,11 +548,11 @@ func TestGroupMediaSeriesCardsKeepsIndependentMoviesSeparateInSharedSubdirectory
 		{LibraryID: "movies", Title: "cd1", Path: `/media/电影/指环王 (2001)/cd1.mkv`},
 		{LibraryID: "movies", Title: "cd2", Path: `/media/电影/指环王 (2001)/cd2.mkv`},
 	}
-		cdCards := groupMediaSeriesCards(cdItems)
-		if len(cdCards) != 1 {
-			t.Fatalf("got %d cards for cd1/cd2, want 1 folded movie card", len(cdCards))
-		}
+	cdCards := groupMediaSeriesCards(cdItems)
+	if len(cdCards) != 1 {
+		t.Fatalf("got %d cards for cd1/cd2, want 1 folded movie card", len(cdCards))
 	}
+}
 
 func TestListMediaEpisodesKeepsIndependentMoviesSeparate(t *testing.T) {
 	db := newServiceTestDB(t, &model.Library{}, &model.Media{})

internal/service/organizer_sidecar.go

@@ -43,7 +43,7 @@ var artworkSidecarSuffixes = []string{
 // artworkSidecarExtensions are the image extensions a sidecar may use. Both
 // "base-poster.jpg" (bare separator) and "base.poster.jpg" (dotted separator)
 // rely on suffix matching, so we probe the common image extensions.
-var artworkSidecarExtensions = []string{".jpg", ".jpeg", ".png", ".webp", ".gif", ".bmp", ".tbn"}
+var artworkSidecarExtensions = []string{".jpg", ".jpeg", ".png", ".webp", ".gif", ".bmp", ".tbn", ".img"}
 
 // transferSidecarArtwork moves/copies/links the scraped poster/backdrop
 // sidecar files alongside its media using the same transfer mode, mirroring

internal/service/scanner_local_ingest.go

@@ -200,7 +200,7 @@ func (s *ScannerService) writeLocalScanMedia(in localScanWriteInput) {
 		in.writeBatch.AddWithAfter(in.path, in.media, in.after)
 		return
 	}
-	if err := s.repo.Media.Upsert(in.ctx, in.media); err != nil {
+	if err := s.repo.Media.UpsertWithAliases(in.ctx, in.media, missingSTRMPathAliases(in.path)); err != nil {
 		addScanError(in.res, in.path, err)
 		s.log.Warn("upsert media failed", zap.String("path", in.path), zap.Error(err))
 		return
@@ -252,8 +252,10 @@ func (s *ScannerService) duplicateByFileID(ctx context.Context, fileID, path str
 }
 
 func (s *ScannerService) mediaPathExists(ctx context.Context, path string) bool {
+	paths := []string{path}
+	paths = append(paths, missingSTRMPathAliases(path)...)
 	var count int64
 	err := s.repo.DB.WithContext(ctx).Unscoped().Model(&model.Media{}).
-		Where("path = ?", path).Count(&count).Error
+		Where("path IN ?", paths).Count(&count).Error
 	return err == nil && count > 0
 }

internal/service/scanner_local_write_batch.go

@@ -7,6 +7,7 @@ import (
 	"go.uber.org/zap"
 
 	"github.com/truewhile/MeBox/internal/model"
+	"github.com/truewhile/MeBox/internal/repository"
 )
 
 type localMediaWriteBatch struct {
@@ -18,9 +19,10 @@ type localMediaWriteBatch struct {
 }
 
 type localMediaWriteItem struct {
-	path  string
-	media *model.Media
-	after func()
+	path    string
+	media   *model.Media
+	aliases []string
+	after   func()
 }
 
 func newLocalMediaWriteBatch(scanner *ScannerService, ctx context.Context, res *ScanResult, limit int) *localMediaWriteBatch {
@@ -41,7 +43,12 @@ func (b *localMediaWriteBatch) AddWithAfter(path string, media *model.Media, aft
 	if media.ScrapeStatus == "" {
 		media.ScrapeStatus = "pending"
 	}
-	b.items = append(b.items, localMediaWriteItem{path: path, media: media, after: after})
+	b.items = append(b.items, localMediaWriteItem{
+		path:    path,
+		media:   media,
+		aliases: missingSTRMPathAliases(path),
+		after:   after,
+	})
 	if len(b.items) >= b.limit {
 		b.Flush()
 	}
@@ -53,39 +60,35 @@ func (b *localMediaWriteBatch) Flush() {
 	}
 	items := b.items
 	b.items = nil
-	media := make([]model.Media, 0, len(items))
-	for _, item := range items {
-		if item.media != nil {
-			media = append(media, *item.media)
-		}
-	}
-	if len(media) == 0 {
-		return
-	}
-	existingPaths := b.existingPaths(items)
-	upsertItems := make([]*model.Media, 0, len(items))
-	upsertAfter := make([]func(), 0, len(items))
+
+	existingPaths, lookupOK := b.existingPathOrAliasSet(items)
+	upsertItems := make([]localMediaWriteItem, 0, len(items))
 	createItems := make([]localMediaWriteItem, 0, len(items))
-	createMedia := make([]model.Media, 0, len(items))
 	for _, item := range items {
 		if item.media == nil {
 			continue
 		}
-		if existingPaths[filepath.Clean(item.media.Path)] {
-			// 已存在行：攒起来在一个事务里逐条 upsert（一批一次提交）。
-			after := item.after
-			upsertItems = append(upsertItems, item.media)
-			upsertAfter = append(upsertAfter, after)
+		// If the alias lookup failed, route through UpsertWithAliases instead of
+		// direct-create. That is slower but cannot create a duplicate row.
+		if !lookupOK || mediaPathOrAliasExists(item.media.Path, item.aliases, existingPaths) {
+			upsertItems = append(upsertItems, item)
 			continue
 		}
 		createItems = append(createItems, item)
-		createMedia = append(createMedia, *item.media)
 	}
-	b.flushUpserts(items, upsertItems, upsertAfter)
-	if len(createMedia) == 0 {
+
+	b.flushUpserts(upsertItems)
+	if len(createItems) == 0 {
 		b.publish()
 		return
 	}
+
+	createMedia := make([]model.Media, 0, len(createItems))
+	for _, item := range createItems {
+		if item.media != nil {
+			createMedia = append(createMedia, *item.media)
+		}
+	}
 	if err := b.scanner.repo.DB.WithContext(b.ctx).CreateInBatches(&createMedia, b.limit).Error; err == nil {
 		b.res.Added += len(createMedia)
 		for _, item := range createItems {
@@ -96,12 +99,13 @@ func (b *localMediaWriteBatch) Flush() {
 		b.publish()
 		return
 	}
+
 	for _, item := range createItems {
 		if item.media == nil {
 			continue
 		}
 		wasExisting := b.mediaPathExists(item.media.Path)
-		if err := b.scanner.repo.Media.Upsert(b.ctx, item.media); err != nil {
+		if err := b.scanner.repo.Media.UpsertWithAliases(b.ctx, item.media, item.aliases); err != nil {
 			addScanError(b.res, item.path, err)
 			b.scanner.log.Warn("upsert media failed", zap.String("path", item.path), zap.Error(err))
 			continue
@@ -118,47 +122,90 @@ func (b *localMediaWriteBatch) Flush() {
 	b.publish()
 }
 
-func (b *localMediaWriteBatch) existingPaths(items []localMediaWriteItem) map[string]bool {
+// existingPathOrAliasSet loads exact and alias paths in bounded query chunks. Aliases
+// have already been filtered against the filesystem by AddWithAfter, so an
+// existing keep_ext sibling is never treated as a rename.
+func (b *localMediaWriteBatch) existingPathOrAliasSet(items []localMediaWriteItem) (map[string]bool, bool) {
 	out := map[string]bool{}
 	if b == nil || b.scanner == nil || b.scanner.repo == nil || b.scanner.repo.DB == nil || len(items) == 0 {
-		return out
+		return out, false
+	}
+	seen := make(map[string]struct{}, len(items)*2)
+	paths := make([]string, 0, len(items)*2)
+	add := func(path string) {
+		path = filepath.Clean(path)
+		if path == "" || path == "." {
+			return
+		}
+		if _, ok := seen[path]; ok {
+			return
+		}
+		seen[path] = struct{}{}
+		paths = append(paths, path)
 	}
-	paths := make([]string, 0, len(items))
 	for _, item := range items {
 		if item.media == nil || item.media.Path == "" {
 			continue
 		}
-		paths = append(paths, item.media.Path)
+		add(item.media.Path)
+		for _, alias := range item.aliases {
+			add(alias)
+		}
 	}
 	if len(paths) == 0 {
-		return out
+		return out, true
 	}
-	var rows []string
-	if err := b.scanner.repo.DB.WithContext(b.ctx).
-		Unscoped().
-		Model(&model.Media{}).
-		Where("path IN ?", paths).
-		Pluck("path", &rows).Error; err != nil {
-		b.scanner.log.Debug("load existing media paths for scan batch failed", zap.Error(err))
-		return out
+	// Keep SQL variables below the legacy SQLite limit (999). A batch can
+	// contain 100 STRM rows and every row has many sibling aliases.
+	const pathLookupChunk = 400
+	for start := 0; start < len(paths); start += pathLookupChunk {
+		end := start + pathLookupChunk
+		if end > len(paths) {
+			end = len(paths)
+		}
+		var rows []string
+		if err := b.scanner.repo.DB.WithContext(b.ctx).
+			Unscoped().
+			Model(&model.Media{}).
+			Where("path IN ?", paths[start:end]).
+			Pluck("path", &rows).Error; err != nil {
+			b.scanner.log.Debug("load existing media paths for scan batch failed", zap.Error(err))
+			return nil, false
+		}
+		for _, path := range rows {
+			out[filepath.Clean(path)] = true
+		}
 	}
-	for _, path := range rows {
-		out[filepath.Clean(path)] = true
-	}
-	return out
+	return out, true
 }
 
-// flushUpserts 把已存在行的 upsert 攒成一个事务（一次提交/一组 fsync）。
-// 整批失败（如单条数据触发约束）时退回逐条 Upsert，只丢真正坏的那几条。
-func (b *localMediaWriteBatch) flushUpserts(allItems []localMediaWriteItem, upsertItems []*model.Media, upsertAfter []func()) {
+func mediaPathOrAliasExists(path string, aliases []string, existing map[string]bool) bool {
+	if existing[filepath.Clean(path)] {
+		return true
+	}
+	for _, alias := range aliases {
+		if existing[filepath.Clean(alias)] {
+			return true
+		}
+	}
+	return false
+}
+
+// flushUpserts 把已存在或可迁移路径的行攒成一个事务（一次提交/一组 fsync）。
+// 整批失败（如单条数据触发约束）时退回逐条 upsert，只丢真正坏的那几条。
+func (b *localMediaWriteBatch) flushUpserts(upsertItems []localMediaWriteItem) {
 	if len(upsertItems) == 0 {
 		return
 	}
-	if err := b.scanner.repo.Media.UpsertBatch(b.ctx, upsertItems); err == nil {
+	batchItems := make([]repository.MediaUpsertItem, 0, len(upsertItems))
+	for _, item := range upsertItems {
+		batchItems = append(batchItems, repository.MediaUpsertItem{Media: item.media, AliasPaths: item.aliases})
+	}
+	if err := b.scanner.repo.Media.UpsertBatchWithAliases(b.ctx, batchItems); err == nil {
 		b.res.Updated += len(upsertItems)
-		for _, after := range upsertAfter {
-			if after != nil {
-				after()
+		for _, item := range upsertItems {
+			if item.after != nil {
+				item.after()
 			}
 		}
 		return
@@ -166,13 +213,7 @@ func (b *localMediaWriteBatch) flushUpserts(allItems []localMediaWriteItem, upse
 		b.scanner.log.Warn("batch upsert failed; falling back to per-item upsert",
 			zap.Int("items", len(upsertItems)))
 	}
-	// 兜底：按原始顺序找回每个条目的 path/after（两个切片同序但可能含 nil）。
-	idx := 0
-	for _, item := range allItems {
-		if item.media == nil || idx >= len(upsertItems) || upsertItems[idx] != item.media {
-			continue
-		}
-		idx++
+	for _, item := range upsertItems {
 		b.upsertExistingItem(item)
 	}
 }
@@ -181,7 +222,7 @@ func (b *localMediaWriteBatch) upsertExistingItem(item localMediaWriteItem) {
 	if item.media == nil {
 		return
 	}
-	if err := b.scanner.repo.Media.Upsert(b.ctx, item.media); err != nil {
+	if err := b.scanner.repo.Media.UpsertWithAliases(b.ctx, item.media, item.aliases); err != nil {
 		addScanError(b.res, item.path, err)
 		b.scanner.log.Warn("upsert media failed", zap.String("path", item.path), zap.Error(err))
 		return

internal/service/scanner_prune.go

@@ -5,13 +5,15 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"time"
 
 	"go.uber.org/zap"
 
 	"github.com/truewhile/MeBox/internal/model"
 )
 
-// RemovePath 物理删除磁盘上已不存在的媒体记录。
+// 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。
 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
@@ -30,24 +32,64 @@ func (s *ScannerService) RemovePath(ctx context.Context, path string) (int64, er
 		Find(&rows).Error; err != nil {
 		return 0, err
 	}
-	ids := make([]string, 0, len(rows))
+	softIDs := make([]string, 0, len(rows))
+	hardIDs := 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。
-		if row.Path == path || strings.HasPrefix(filepath.Clean(row.Path), prefix) {
-			ids = append(ids, row.ID)
+		if row.Path != path && !strings.HasPrefix(filepath.Clean(row.Path), prefix) {
+			continue
 		}
+		// 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.
+		if row.Path == path && liveSTRMPathAlias(path) {
+			softIDs = append(softIDs, row.ID)
+			continue
+		}
+		hardIDs = append(hardIDs, row.ID)
 	}
-	if len(ids) == 0 {
-		return 0, nil
+	var removed int64
+	if len(softIDs) > 0 {
+		res := s.repo.DB.WithContext(ctx).
+			Where("id IN ?", softIDs).
+			Delete(&model.Media{})
+		if res.Error != nil {
+			return removed, res.Error
+		}
+		removed += res.RowsAffected
 	}
-	res := s.repo.DB.WithContext(ctx).Unscoped().
-		Where("id IN ?", ids).
-		Delete(&model.Media{})
-	if res.Error == nil && res.RowsAffected > 0 {
+	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
+		}
+		removed += res.RowsAffected
+	}
+	if removed > 0 {
 		s.invalidateMediaCache(ctx)
 	}
-	return res.RowsAffected, res.Error
+	if len(softIDs) > 0 {
+		s.purgeExpiredSTRMTombstones(ctx)
+	}
+	return removed, nil
+}
+
+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.
+func (s *ScannerService) purgeExpiredSTRMTombstones(ctx context.Context) {
+	cutoff := time.Now().Add(-strmRenameTombstoneRetention)
+	if err := s.repo.DB.WithContext(ctx).Unscoped().
+		Where("deleted_at IS NOT NULL AND deleted_at < ? AND path LIKE ?", cutoff, "%.strm").
+		Delete(&model.Media{}).Error; err != nil && s.log != nil {
+		s.log.Warn("purge expired STRM rename tombstones failed", zap.Error(err))
+	}
 }
 
 func (s *ScannerService) pruneMissingMedia(ctx context.Context, libraryID string, seen map[string]struct{}) (int64, error) {

internal/service/scanner_scan.go

@@ -117,6 +117,10 @@ func (s *ScannerService) scanLibrary(ctx context.Context, libraryID string, auto
 			}
 			continue
 		}
+		// Flush alias-aware upserts before pruning missing paths. This lets a
+		// foo.strm <-> foo.mkv.strm rename migrate the existing row (including
+		// scraped metadata) instead of deleting it as "old path missing".
+		writeBatch.Flush()
 		scannedRoots++
 		removed, err := s.pruneMissingMediaForRoot(ctx, lib.ID, root.ID, root.Path, seen)
 		if err != nil {

internal/service/scanner_strm_rename_test.go

@@ -0,0 +1,212 @@
+package service
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/truewhile/MeBox/internal/model"
+)
+
+func TestSTRMPathAliasesCoverBothKeepExtDirections(t *testing.T) {
+	toKeepExt := strmPathAliases(filepath.Join(t.TempDir(), "Show.S01E01.strm"))
+	if !containsPathAlias(toKeepExt, "Show.S01E01.mkv.strm") {
+		t.Fatalf("missing keep_ext alias: %#v", toKeepExt)
+	}
+	fromKeepExt := strmPathAliases(filepath.Join(t.TempDir(), "Show.S01E01.mkv.strm"))
+	if !containsPathAlias(fromKeepExt, "Show.S01E01.strm") {
+		t.Fatalf("missing stripped alias: %#v", fromKeepExt)
+	}
+}
+
+func TestMissingSTRMPathAliasesKeepsRealKeepExtSiblingVersions(t *testing.T) {
+	dir := t.TempDir()
+	current := filepath.Join(dir, "Show.S01E01.mkv.strm")
+	sibling := filepath.Join(dir, "Show.S01E01.mp4.strm")
+	writeFileContent(t, current, "https://example.test/mkv")
+	writeFileContent(t, sibling, "https://example.test/mp4")
+
+	aliases := missingSTRMPathAliases(current)
+	if containsPathAlias(aliases, sibling) {
+		t.Fatalf("existing keep_ext sibling must remain a separate version: %#v", aliases)
+	}
+}
+
+func TestScanLibraryMigratesSTRMKeepExtRename(t *testing.T) {
+	cases := []struct {
+		name    string
+		oldName string
+		newName string
+	}{
+		{name: "add video extension", oldName: "Show.S01E01.strm", newName: "Show.S01E01.mkv.strm"},
+		{name: "remove video extension", oldName: "Show.S01E01.mkv.strm", newName: "Show.S01E01.strm"},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			sc, repos := newScannerTestEnv(t)
+			root := t.TempDir()
+			lib := model.Library{Name: "Anime", Path: root, Type: "anime", Enabled: true}
+			if err := repos.Library.Create(t.Context(), &lib); err != nil {
+				t.Fatal(err)
+			}
+			oldPath := filepath.Join(root, tc.oldName)
+			newPath := filepath.Join(root, tc.newName)
+			writeFileContent(t, oldPath, "https://example.test/video")
+			if _, err := sc.IngestPath(t.Context(), lib.ID, oldPath); err != nil {
+				t.Fatal(err)
+			}
+
+			var before model.Media
+			if err := repos.DB.First(&before, "path = ?", oldPath).Error; err != nil {
+				t.Fatal(err)
+			}
+			if err := repos.DB.Model(&model.Media{}).Where("id = ?", before.ID).Updates(map[string]any{
+				"title":         "地狱乐",
+				"original_name": "Jigokuraku",
+				"overview":      "preserved overview",
+				"poster_url":    "Jigokuraku-poster.jpg",
+				"backdrop_url":  "Jigokuraku-backdrop.jpg",
+				"year":          2023,
+				"rating":        8.6,
+				"tm_db_id":      12345,
+				"bangumi_id":    67890,
+				"genres":        "Action,Adventure",
+				"scrape_status": "matched",
+			}).Error; err != nil {
+				t.Fatal(err)
+			}
+			if err := os.Rename(oldPath, newPath); err != nil {
+				t.Fatal(err)
+			}
+
+			res, err := sc.ScanLibrary(t.Context(), lib.ID)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if res.ErrorCount != 0 {
+				t.Fatalf("scan errors: %#v", res.Errors)
+			}
+			if got := countMedia(t, repos); got != 1 {
+				t.Fatalf("media count = %d, want 1", got)
+			}
+
+			var after model.Media
+			if err := repos.DB.First(&after, "id = ?", before.ID).Error; err != nil {
+				t.Fatalf("old media row was not preserved: %v", err)
+			}
+			if after.Path != newPath {
+				t.Fatalf("path = %q, want %q", after.Path, newPath)
+			}
+			if after.Title != "地狱乐" || after.OriginalName != "Jigokuraku" || after.Overview != "preserved overview" {
+				t.Fatalf("scraped identity metadata was lost: %#v", after)
+			}
+			if after.PosterURL != "Jigokuraku-poster.jpg" || after.BackdropURL != "Jigokuraku-backdrop.jpg" {
+				t.Fatalf("artwork was lost: poster=%q backdrop=%q", after.PosterURL, after.BackdropURL)
+			}
+			if after.TMDbID != 12345 || after.BangumiID != 67890 || after.ScrapeStatus != "matched" {
+				t.Fatalf("scrape IDs/status changed: tmdb=%d bgm=%d status=%q", after.TMDbID, after.BangumiID, after.ScrapeStatus)
+			}
+		})
+	}
+}
+
+func TestIngestPathAdoptsSoftDeletedSTRMRenameTombstone(t *testing.T) {
+	sc, repos := newScannerTestEnv(t)
+	root := t.TempDir()
+	lib := model.Library{Name: "Anime", Path: root, Type: "anime", Enabled: true}
+	if err := repos.Library.Create(t.Context(), &lib); err != nil {
+		t.Fatal(err)
+	}
+	oldPath := filepath.Join(root, "Show.S01E01.mkv.strm")
+	newPath := filepath.Join(root, "Show.S01E01.strm")
+	writeFileContent(t, oldPath, "https://example.test/video")
+	if _, err := sc.IngestPath(t.Context(), lib.ID, oldPath); err != nil {
+		t.Fatal(err)
+	}
+
+	var before model.Media
+	if err := repos.DB.First(&before, "path = ?", oldPath).Error; err != nil {
+		t.Fatal(err)
+	}
+	if err := repos.DB.Model(&model.Media{}).Where("id = ?", before.ID).Updates(map[string]any{
+		"title":         "拔作岛",
+		"overview":      "kept through remove-before-create",
+		"poster_url":    "nukitashi-poster.webp",
+		"tm_db_id":      222,
+		"scrape_status": "matched",
+	}).Error; err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Rename(oldPath, newPath); err != nil {
+		t.Fatal(err)
+	}
+
+	// Simulate fsnotify delivering Remove(old) before Create(new).
+	if removed, err := sc.RemovePath(t.Context(), oldPath); err != nil || removed != 1 {
+		t.Fatalf("RemovePath() removed=%d err=%v, want 1", removed, err)
+	}
+	var tombstone model.Media
+	if err := repos.DB.Unscoped().First(&tombstone, "id = ?", before.ID).Error; err != nil {
+		t.Fatal(err)
+	}
+	if !tombstone.DeletedAt.Valid {
+		t.Fatal("rename tombstone should be soft-deleted")
+	}
+	if got := countMedia(t, repos); got != 0 {
+		t.Fatalf("active media count = %d, want 0 before create event", got)
+	}
+
+	if _, err := sc.IngestPath(t.Context(), lib.ID, newPath); err != nil {
+		t.Fatal(err)
+	}
+	var after model.Media
+	if err := repos.DB.First(&after, "id = ?", before.ID).Error; err != nil {
+		t.Fatalf("soft-deleted row was not restored: %v", err)
+	}
+	if after.Path != newPath || after.Title != "拔作岛" || after.Overview != "kept through remove-before-create" {
+		t.Fatalf("rename metadata was not adopted: %#v", after)
+	}
+	if after.TMDbID != 222 || after.ScrapeStatus != "matched" {
+		t.Fatalf("scrape metadata changed: tmdb=%d status=%q", after.TMDbID, after.ScrapeStatus)
+	}
+	if got := countMedia(t, repos); got != 1 {
+		t.Fatalf("media count = %d, want 1", got)
+	}
+}
+
+func TestRemovePathStillHardDeletesTrueDeletionWithoutAlias(t *testing.T) {
+	sc, repos := newScannerTestEnv(t)
+	root := t.TempDir()
+	lib := model.Library{Name: "Anime", Path: root, Type: "anime", Enabled: true}
+	if err := repos.Library.Create(t.Context(), &lib); err != nil {
+		t.Fatal(err)
+	}
+	path := filepath.Join(root, "Deleted.S01E01.mkv.strm")
+	writeFileContent(t, path, "https://example.test/video")
+	if _, err := sc.IngestPath(t.Context(), lib.ID, path); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Remove(path); err != nil {
+		t.Fatal(err)
+	}
+	if removed, err := sc.RemovePath(t.Context(), path); err != nil || removed != 1 {
+		t.Fatalf("RemovePath() removed=%d err=%v, want 1", removed, err)
+	}
+	var count int64
+	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)
+	}
+}
+
+func containsPathAlias(paths []string, name string) bool {
+	for _, path := range paths {
+		if strings.EqualFold(filepath.Base(path), filepath.Base(name)) {
+			return true
+		}
+	}
+	return false
+}

internal/service/scraper_query_test.go

@@ -48,6 +48,17 @@ func TestCleanQuery(t *testing.T) {
 	}
 }
 
+func TestCleanQueryIgnoresKeepExtSTRMSuffix(t *testing.T) {
+	plain := filepath.Join("/media/anime", "Jigokuraku 2023 S01E14.strm")
+	keepExt := filepath.Join("/media/anime", "Jigokuraku 2023 S01E14.mkv.strm")
+	plainTitle, plainYear := CleanQuery(plain)
+	keepTitle, keepYear := CleanQuery(keepExt)
+	if plainTitle != keepTitle || plainYear != keepYear {
+		t.Fatalf("keep_ext changed scrape identity: plain=(%q,%d) keep_ext=(%q,%d)",
+			plainTitle, plainYear, keepTitle, keepYear)
+	}
+}
+
 func TestScrapeQueryCandidatesCleanDirtySeriesFolder(t *testing.T) {
 	lib := &model.Library{
 		Path: `F:\media\电视剧\欧美剧`,

internal/service/strm_service.go

@@ -49,7 +49,7 @@ const (
 
 const (
 	StrmDefaultVideoExt = "mkv,mp4,avi,rmvb,rm,mov,ts,wmv,flv,m4v,iso,mpg,mpeg,webm"
-	StrmDefaultMetaExt  = "nfo,jpg,jpeg,png,srt,ass,ssa,sub,txt,bmp,webp"
+	StrmDefaultMetaExt  = "nfo,jpg,jpeg,png,srt,ass,ssa,sub,txt,bmp,webp,img"
 	StrmDefaultExclude  = "sample,trailer,预告"
 )
 

internal/service/strm_sync.go

@@ -612,6 +612,12 @@ func (st *strmSyncState) isVideoExt(ext string, size int64) bool {
 }
 
 func (st *strmSyncState) isMetaExt(ext string) bool {
+	// Legacy MeBox installs may have persisted strm.meta_ext without img.
+	// .img is emitted by the artwork writer as a fallback image container, so
+	// keep accepting existing sidecars without requiring a settings migration.
+	if strings.EqualFold(ext, ".img") {
+		return true
+	}
 	for _, e := range st.cfg.MetaExt {
 		if "."+e == ext {
 			return true

internal/service/strm_sync_test.go

@@ -1680,3 +1680,10 @@ func TestHandleVideoKeepExtWritesAllVersions(t *testing.T) {
 		t.Fatalf("NewStrm=%d want 2", st.rec.NewStrm)
 	}
 }
+
+func TestStrmSyncTreatsLegacyImgAsMetadata(t *testing.T) {
+	st := &strmSyncState{cfg: &strmPathConfig{MetaExt: csvSplit("nfo,jpg")}}
+	if !st.isMetaExt(".img") {
+		t.Fatal("legacy .img sidecars must remain metadata even when an old setting omits img")
+	}
+}

web/src/api/danmaku.ts

@@ -27,20 +27,32 @@ export interface DanmakuFetchResult {
   font_size: string
   area: string
   raw?: string
+  /** Number of sources merged into `raw`; absent/0 means not merged. */
+  merged_sources?: number
   candidates?: DanmakuAnime[]
+  /**
+   * Same episode, other sources. Unlike `candidates` (which means "pick one
+   * before anything loads"), `alternatives` arrives together with a loaded
+   * library: the backend already auto-picked one and offers the rest so the
+   * user can switch without re-searching. Aggregating sources such as LogVar
+   * return several libraries for the same episode.
+   */
+  alternatives?: DanmakuAnime[]
   anime_title?: string
   episode_title?: string
   episode_id?: number
-  match_mode?: 'hash' | 'filename' | 'search' | 'manual' | string
+  match_mode?: 'hash' | 'filename' | 'metadata' | 'search' | 'manual' | string
 }
 
 export interface DanmakuLoadedInfo {
   animeTitle?: string
   episodeTitle?: string
   episodeId?: number | string
-  matchMode?: 'hash' | 'filename' | 'search' | 'manual' | string
+  matchMode?: 'hash' | 'filename' | 'metadata' | 'search' | 'manual' | string
   totalCount: number
   sourceType?: 'auto' | 'xml' | 'json'
+  /** Number of sources merged into the loaded comments (0 = not merged). */
+  mergedSources?: number
 }
 
 export type DanmakuFetchOptions = {
@@ -73,6 +85,16 @@ export const danmakuAPI = {
         opacity: string
         font_size: string
         area: string
+        /** Per-user preference: merge the same episode's multiple sources. */
+        merge_sources: boolean
       }>('/danmaku/config')
       .then((r) => r.data),
-}
+
+  // updateSettings persists per-user danmaku preferences (survives reload).
+  updateSettings: (settings: { mergeSources: boolean }) =>
+    api
+      .put<{ merge_sources: boolean }>('/danmaku/settings', {
+        merge_sources: settings.mergeSources,
+      })
+      .then((r) => r.data),
+}

web/src/components/DanmakuStage.tsx

@@ -34,6 +34,8 @@ type DanmakuStageProps = {
   onLoaded?: (info: DanmakuLoadedInfo | null) => void
   /** Called when multiple anime matched and the user must pick one. */
   onCandidates?: (candidates: DanmakuAnime[]) => void
+  /** Called after a successful load with other libraries for the same episode. */
+  onAlternatives?: (alternatives: DanmakuAnime[]) => void
 }
 
 // Average of the engine's durationRange (ms). Used to compute how far a
@@ -55,6 +57,7 @@ export function DanmakuStage({
   searchTrigger = 0,
   onLoaded,
   onCandidates,
+  onAlternatives,
 }: DanmakuStageProps) {
   const holderRef = useRef<HTMLDivElement>(null)
   const managerRef = useRef<Manager<Comment> | null>(null)
@@ -143,10 +146,13 @@ export function DanmakuStage({
         if (res.candidates && res.candidates.length > 0) {
           // 多番剧命中：交回播放器展示候选让用户选择（disambiguation）。
           comments = []
+          onAlternatives?.([])
           onCandidates?.(res.candidates)
           return
         }
         if (res.enabled) {
+          // 弹幕已自动加载；若同一集还有其它来源，一并交回播放器供随时切换。
+          onAlternatives?.(res.alternatives ?? [])
           comments = parseDanmaku(res.raw || '', res.source_type)
             .filter((c) => Number.isFinite(c.time) && c.time >= 0)
             .sort((a, b) => a.time - b.time)
@@ -158,9 +164,11 @@ export function DanmakuStage({
             matchMode: res.match_mode,
             totalCount: comments.length,
             sourceType: res.source_type,
+            mergedSources: res.merged_sources ?? 0,
           }
         } else {
           comments = []
+          onAlternatives?.([])
           loadedInfo = {
             totalCount: 0,
           }

web/src/components/LayoutHeaderSections.tsx

@@ -114,16 +114,24 @@ function LayoutHeaderSearch() {
   const [loading, setLoading] = useState(false)
   const [results, setResults] = useState<Media[]>([])
   const containerRef = useRef<HTMLDivElement>(null)
+  const isOpenRef = useRef(false)
   // 递增序号守卫：快速连续输入时丢弃过期响应
   const searchSeqRef = useRef(0)
   const navigate = useNavigate()
 
+  const setSearchOpen = (open: boolean) => {
+    isOpenRef.current = open
+    setIsOpen(open)
+  }
+
   useEffect(() => {
     const trimmed = query.trim()
     if (!trimmed) {
       searchSeqRef.current += 1
       setResults([])
       setLoading(false)
+      isOpenRef.current = false
+      setIsOpen(false)
       return
     }
 
@@ -134,7 +142,7 @@ function LayoutHeaderSearch() {
         const res = await mediaAPI.search(trimmed, 8)
         if (seq !== searchSeqRef.current) return
         setResults(res.items || [])
-        setIsOpen(true)
+        if (isOpenRef.current) setIsOpen(true)
       } catch {
         // 请求失败时保留旧结果，避免网络抖动清空下拉
       } finally {
@@ -148,6 +156,7 @@ function LayoutHeaderSearch() {
   useEffect(() => {
     function handleClickOutside(e: MouseEvent) {
       if (containerRef.current && !containerRef.current.contains(e.target as Node)) {
+        isOpenRef.current = false
         setIsOpen(false)
       }
     }
@@ -156,14 +165,14 @@ function LayoutHeaderSearch() {
   }, [])
 
   const handleSelect = (item: Media) => {
-    setIsOpen(false)
+    setSearchOpen(false)
     setQuery('')
     navigate(favouriteMediaLink(item))
   }
 
   const handleKeyDown = (e: React.KeyboardEvent) => {
     if (e.key === 'Escape') {
-      setIsOpen(false)
+      setSearchOpen(false)
     } else if (e.key === 'Enter' && results.length > 0) {
       handleSelect(results[0])
     }
@@ -180,11 +189,12 @@ function LayoutHeaderSearch() {
           type="text"
           value={query}
           onChange={(e) => {
-            setQuery(e.target.value)
-            if (e.target.value.trim()) setIsOpen(true)
+            const nextQuery = e.target.value
+            setQuery(nextQuery)
+            setSearchOpen(Boolean(nextQuery.trim()))
           }}
           onFocus={() => {
-            if (results.length > 0) setIsOpen(true)
+            if (query.trim()) setSearchOpen(true)
           }}
           onKeyDown={handleKeyDown}
           placeholder="搜索媒体…"
@@ -198,7 +208,7 @@ function LayoutHeaderSearch() {
             onClick={() => {
               setQuery('')
               setResults([])
-              setIsOpen(false)
+              setSearchOpen(false)
             }}
             className="absolute right-3 text-[var(--app-muted)] hover:text-[var(--app-text)] p-0.5 rounded-lg"
           >

web/src/components/PlayerDanmakuPanel.tsx

@@ -23,6 +23,16 @@ type PlayerDanmakuPanelProps = {
   onFontSizeChange: (v: number) => void
   /** Multiple anime matched — user must pick one. */
   candidates: DanmakuAnime[]
+  /**
+   * Other libraries holding this same episode. Danmaku is already loaded from
+   * one of them; these exist so the user can switch sources on the spot.
+   */
+  alternatives: DanmakuAnime[]
+  /** Per-user preference: merge the same episode's sources into one list. */
+  mergeSources: boolean
+  onMergeSourcesChange: (v: boolean) => void
+  /** True while the merge preference is being persisted. */
+  mergeSaving?: boolean
   /** Human-readable label of the currently selected library. */
   selectedSource?: string
   /** Title used by auto-matching (e.g. anime title, media title or filename). */
@@ -48,6 +58,10 @@ export function PlayerDanmakuPanel({
   fontSize,
   onFontSizeChange,
   candidates,
+  alternatives,
+  mergeSources,
+  onMergeSourcesChange,
+  mergeSaving = false,
   selectedSource,
   autoMatchTitle,
   danmakuInfo,
@@ -95,6 +109,12 @@ export function PlayerDanmakuPanel({
             <Tag size={10} /> 文件名匹配
           </span>
         )
+      case 'metadata':
+        return (
+          <span className="inline-flex items-center gap-0.5 rounded border border-cyan-500/30 bg-cyan-500/15 px-1.5 py-0.5 text-[10px] font-medium text-cyan-300">
+            <Search size={10} /> 刮削信息匹配
+          </span>
+        )
       case 'search':
         return (
           <span className="inline-flex items-center gap-0.5 rounded border border-violet-500/30 bg-violet-500/15 px-1.5 py-0.5 text-[10px] font-medium text-violet-300">
@@ -114,6 +134,11 @@ export function PlayerDanmakuPanel({
 
   const isCustomOrManual = Boolean(search || selectedSource || danmakuInfo?.matchMode === 'manual')
 
+  // 候选来源摊平成「番剧 + 集」的一维列表：每个来源通常只含命中的那一集。
+  const alternativeRows = alternatives.flatMap((anime) =>
+    anime.episodes.map((ep) => ({ anime, ep })),
+  )
+
   return (
     // 面板悬浮于视频上方：阻止点击冒泡，避免触发视频区域的播放/暂停切换。
     <div
@@ -286,6 +311,83 @@ export function PlayerDanmakuPanel({
         </div>
       )}
 
+      {/* 同集其它来源：弹幕已自动加载，这里直接切换即可 */}
+      {enabled && alternatives.length > 0 && (
+        <div className="mb-4 rounded-xl border border-sky-400/25 bg-sky-400/5 p-2.5">
+          <div className="mb-1.5 px-1 text-xs font-medium text-sky-200">
+            同集其它来源（{alternativeRows.length}）
+          </div>
+          <div className="mb-1.5 px-1 text-[10px] leading-relaxed text-white/45">
+            当前已自动加载一个来源，点其它条目可直接切换，无需重新搜索。
+          </div>
+          <div className="max-h-52 overflow-y-auto pr-1">
+            {alternativeRows.map(({ anime, ep }, i) => {
+              const current = String(danmakuInfo?.episodeId ?? '') === String(ep.episodeId)
+              return (
+                <button
+                  key={`${anime.animeId}-${ep.episodeId}-${i}`}
+                  onClick={() => onSelectEpisode(ep.episodeId, anime.animeTitle, ep.episodeTitle)}
+                  className={
+                    'mb-1 flex w-full items-start gap-1.5 rounded-md px-1.5 py-1.5 text-left text-xs transition ' +
+                    (current
+                      ? 'bg-sky-500/20 text-white'
+                      : 'text-white/70 hover:bg-sky-500/15 hover:text-white')
+                  }
+                  title={`切换到《${anime.animeTitle}》的《${ep.episodeTitle}》`}
+                >
+                  <span className="mt-0.5 shrink-0">
+                    {current ? (
+                      <Check size={12} className="text-sky-300" />
+                    ) : (
+                      <Film size={12} className="text-white/35" />
+                    )}
+                  </span>
+                  <span className="min-w-0 flex-1">
+                    <span className="block truncate">{anime.animeTitle || `来源 ${i + 1}`}</span>
+                    {ep.episodeTitle && (
+                      <span className="mt-0.5 block truncate text-[10px] text-white/50">
+                        {ep.episodeTitle}
+                      </span>
+                    )}
+                  </span>
+                  {current && (
+                    <span className="mt-0.5 shrink-0 text-[10px] text-sky-300">当前</span>
+                  )}
+                </button>
+              )
+            })}
+          </div>
+        </div>
+      )}
+
+      {/* 合并多来源：仅在确实存在多个同集来源时才出现，避免无意义的开关 */}
+      {enabled && alternativeRows.length > 1 && (
+        <div className="mb-4 rounded-xl border border-emerald-400/25 bg-emerald-400/5 p-2.5">
+          <label className="flex cursor-pointer items-start justify-between gap-2">
+            <span className="min-w-0">
+              <span className="block text-xs font-medium text-emerald-200">合并多来源弹幕</span>
+              <span className="mt-0.5 block text-[10px] leading-relaxed text-white/45">
+                把以上来源的弹幕合并，并按时间与内容去重后一起显示。该设置会保存到账号。
+              </span>
+            </span>
+            <span className="flex shrink-0 items-center gap-1.5 pt-0.5">
+              {mergeSaving && <Loader2 size={11} className="animate-spin text-emerald-300" />}
+              <input
+                type="checkbox"
+                checked={mergeSources}
+                onChange={(e) => onMergeSourcesChange(e.target.checked)}
+                className="h-4 w-4 accent-emerald-500"
+              />
+            </span>
+          </label>
+          {mergeSources && danmakuInfo?.mergedSources ? (
+            <div className="mt-1.5 border-t border-white/10 pt-1.5 text-[10px] text-emerald-300/80">
+              已合并 {danmakuInfo.mergedSources} 个来源
+            </div>
+          ) : null}
+        </div>
+      )}
+
       {/* 屏幕占比（显示区域） */}
       <SliderRow
         label="屏幕占比"
@@ -373,4 +475,4 @@ function EpisodeRow({
       <span className="min-w-0 flex-1 truncate">{episode.episodeTitle}</span>
     </button>
   )
-}
+}

web/src/hooks/useWebSocket.ts

@@ -7,6 +7,32 @@ import { useAuthStore } from '../stores/auth'
 const FAST_RECONNECT_ATTEMPTS = 5
 const SLOW_RECONNECT_INTERVAL = 60_000
 
+// token 过期前 30 秒即视为失效，给刷新留出余量。
+const TOKEN_EXPIRY_SKEW_MS = 30_000
+
+// decodeJwtExpiryMs 解析 JWT 的 exp 声明并换算成毫秒时间戳。
+// 解析失败（非 JWT / 结构异常）返回 null，调用方据此放行重连。
+function decodeJwtExpiryMs(token: string): number | null {
+  const segment = token.split('.')[1]
+  if (!segment) return null
+  try {
+    // JWT 使用 base64url 编码，需先还原字符集并补齐 padding。
+    const normalized = segment.replace(/-/g, '+').replace(/_/g, '/')
+    const padded = normalized.padEnd(Math.ceil(normalized.length / 4) * 4, '=')
+    const claims = JSON.parse(atob(padded)) as { exp?: unknown }
+    return typeof claims.exp === 'number' ? claims.exp * 1000 : null
+  } catch {
+    return null
+  }
+}
+
+// isTokenExpired 判断 token 是否已过期或即将过期。
+function isTokenExpired(token: string): boolean {
+  const expiry = decodeJwtExpiryMs(token)
+  if (expiry === null) return false
+  return Date.now() >= expiry - TOKEN_EXPIRY_SKEW_MS
+}
+
 // useWebSocket opens a single connection to /api/ws and dispatches every
 // message to the supplied handler. Auto-reconnects with back-off while the
 // auth token is present; after the fast retries are exhausted it keeps a
@@ -28,6 +54,13 @@ export function useWebSocket(onEvent: (topic: string, payload: unknown) => void)
 
     const open = () => {
       if (closed) return
+      // 过期的 token 握手必然 401。此前这里会以 60s 间隔无限重试，服务端
+      // 日志里表现为每分钟一条 401。改为先走刷新流程：成功会更新 token 并
+      // 让本 effect 重建连接，失败则清空会话停止重连。
+      if (isTokenExpired(token)) {
+        void useAuthStore.getState().tokenRefresh()
+        return
+      }
       const proto = window.location.protocol === 'https:' ? 'wss:' : 'ws:'
       const url = `${proto}//${window.location.host}/api/ws?token=${encodeURIComponent(token)}`
       const ws = new WebSocket(url)
@@ -47,6 +80,11 @@ export function useWebSocket(onEvent: (topic: string, payload: unknown) => void)
       }
       ws.onclose = () => {
         if (closed) return
+        // token 过期时不要继续退避重试，交给刷新流程处理。
+        if (isTokenExpired(token)) {
+          void useAuthStore.getState().tokenRefresh()
+          return
+        }
         reconnectAttempts += 1
         // 快速阶段保持原有线性退避，之后固定 60s 慢速重试；
         // timer 始终只有一个在途，cleanup 时统一清除，不会堆积。

web/src/pages/PlayerPage.tsx

@@ -98,10 +98,15 @@ export function PlayerPage() {
   const [danmakuEpisodeId, setDanmakuEpisodeId] = useState<number | string | null>(null)
   // 自动匹配歧义（多番剧命中）时的候选列表。
   const [danmakuCandidates, setDanmakuCandidates] = useState<DanmakuAnime[]>([])
+  // 同一集的其它可选来源（弹幕已自动加载，用户可随时切换，无需重新搜索）。
+  const [danmakuAlternatives, setDanmakuAlternatives] = useState<DanmakuAnime[]>([])
   // 已加载弹幕的元数据信息（番剧名、单集名、条数、匹配模式等）。
   const [danmakuInfo, setDanmakuInfo] = useState<DanmakuLoadedInfo | null>(null)
   // 用户当前选定的弹幕来源描述（面板中展示）。
   const [danmakuSelectedSource, setDanmakuSelectedSource] = useState('')
+  // 弹幕合并偏好：从 /danmaku/config 读取（按用户落库），切换后写回并重新抓取。
+  const [danmakuMergeSources, setDanmakuMergeSources] = useState(false)
+  const [danmakuMergeSaving, setDanmakuMergeSaving] = useState(false)
   const [danmakuOpacity, setDanmakuOpacity] = useState(1)
   const [danmakuFontSize, setDanmakuFontSize] = useState(24)
   const [danmakuArea, setDanmakuArea] = useState(1)
@@ -168,11 +173,45 @@ export function PlayerPage() {
       .catch(() => undefined)
   }, [])
 
+  // 读取弹幕配置（含按用户存储的合并偏好），初始化面板。
+  useEffect(() => {
+    let cancelled = false
+    danmakuAPI
+      .config()
+      .then((cfg) => {
+        if (cancelled) return
+        setDanmakuMergeSources(Boolean(cfg.merge_sources))
+      })
+      .catch(() => {
+        // 配置读取失败时保持默认（不合并），不影响播放。
+      })
+    return () => {
+      cancelled = true
+    }
+  }, [])
+
+  // 切换合并开关：先落库，成功后再重新抓取，避免与后端读到的偏好不一致。
+  const danmakuChangeMergeSources = useCallback((next: boolean) => {
+    setDanmakuMergeSaving(true)
+    danmakuAPI
+      .updateSettings({ mergeSources: next })
+      .then(() => {
+        setDanmakuMergeSources(next)
+        setDanmakuSearching(true)
+        setDanmakuSearchTrigger((prev) => prev + 1)
+      })
+      .catch(() => {
+        // 保存失败时保持原值，用户可重试。
+      })
+      .finally(() => setDanmakuMergeSaving(false))
+  }, [])
+
   // 用户手动搜索：带关键词重新拉取（search=null 时按视频名）。
   // loading 状态由 DanmakuStage 拉取完成回调（onLoaded）驱动。
   const searchDanmaku = useCallback((kw: string) => {
     setDanmakuSearching(true)
     setDanmakuCandidates([])
+    setDanmakuAlternatives([])
     setDanmakuEpisodeId(null)
     setDanmakuInfo(null)
     setDanmakuSearch(kw || null)
@@ -184,6 +223,11 @@ export function PlayerPage() {
     setDanmakuInfo(info)
   }, [])
 
+  // 同一集的其它来源：弹幕已自动加载好，这里只更新可切换列表。
+  const danmakuGotAlternatives = useCallback((alternatives: DanmakuAnime[]) => {
+    setDanmakuAlternatives(alternatives)
+  }, [])
+
   // 多番剧命中（disambiguation）：展示候选让用户选择。
   const danmakuGotCandidates = useCallback((candidates: DanmakuAnime[]) => {
     setDanmakuCandidates(candidates)
@@ -197,6 +241,8 @@ export function PlayerPage() {
   const danmakuSelectEpisode = useCallback((episodeId: number, animeTitle: string, episodeTitle: string) => {
     setDanmakuEpisodeId(episodeId)
     setDanmakuCandidates([])
+    // 刻意不清空 danmakuAlternatives：切到别的来源后仍要能继续切换回去，
+    // 否则用户每次都得重新搜一遍。
     setDanmakuSearching(true)
     // 展示当前所选来源（面板标题处可见）。
     setDanmakuSelectedSource(episodeTitle ? `${animeTitle}・${episodeTitle}` : animeTitle)
@@ -207,6 +253,7 @@ export function PlayerPage() {
   const danmakuResetAuto = useCallback(() => {
     setDanmakuEpisodeId(null)
     setDanmakuCandidates([])
+    setDanmakuAlternatives([])
     setDanmakuSearching(true)
     setDanmakuSearch(null)
     setDanmakuSelectedSource('')
@@ -221,6 +268,7 @@ export function PlayerPage() {
     setHlsStartSec(0)
     setDanmakuEpisodeId(null)
     setDanmakuCandidates([])
+    setDanmakuAlternatives([])
     setDanmakuSearch(null)
     setDanmakuSelectedSource('')
     setDanmakuInfo(null)
@@ -947,6 +995,7 @@ export function PlayerPage() {
         onToggleDanmaku={toggleDanmakuOpen}
         onDanmakuLoaded={danmakuLoaded}
         onDanmakuCandidates={danmakuGotCandidates}
+        onDanmakuAlternatives={danmakuGotAlternatives}
         hasPrevEpisode={Boolean(prevEpisode)}
         hasNextEpisode={Boolean(nextEpisode)}
         onPrevEpisode={handlePrevEpisode}
@@ -984,6 +1033,10 @@ export function PlayerPage() {
             fontSize={danmakuFontSize}
             onFontSizeChange={setDanmakuFontSize}
             candidates={danmakuCandidates}
+            alternatives={danmakuAlternatives}
+            mergeSources={danmakuMergeSources}
+            onMergeSourcesChange={danmakuChangeMergeSources}
+            mergeSaving={danmakuMergeSaving}
             selectedSource={danmakuSelectedSource}
             autoMatchTitle={danmakuAutoTitle}
             danmakuInfo={danmakuInfo}

web/src/pages/PlayerVideoStage.tsx

@@ -158,6 +158,7 @@ type PlayerVideoStageProps = {
   onToggleDanmaku: () => void
   onDanmakuLoaded: (info: DanmakuLoadedInfo | null) => void
   onDanmakuCandidates: (candidates: DanmakuAnime[]) => void
+  onDanmakuAlternatives: (alternatives: DanmakuAnime[]) => void
   /** Danmaku settings panel; rendered inside the stage so it stays visible in fullscreen. */
   danmakuPanel: ReactNode
   /** Playlist drawer / panel; rendered inside the stage so it stays visible in fullscreen. */
@@ -202,6 +203,7 @@ export function PlayerVideoStage({
   onToggleDanmaku,
   onDanmakuLoaded,
   onDanmakuCandidates,
+  onDanmakuAlternatives,
   danmakuPanel,
   playlistPanel,
   hasPrevEpisode,
@@ -588,6 +590,7 @@ export function PlayerVideoStage({
               searchTrigger={danmakuSearchTrigger}
               onLoaded={onDanmakuLoaded}
               onCandidates={onDanmakuCandidates}
+              onAlternatives={onDanmakuAlternatives}
             />
             {tracksArmed && media && assTrack && assFallbackPath !== assTrack.path ? (
               <AssSubtitleStage

web/src/utils/groupSeries.ts

@@ -480,20 +480,31 @@ export function groupSeries(items: Media[] = []): SeriesCard[] {
       if (betterSeriesLinkMedia(m, g.linkMedia)) {
         g.linkMedia = m
       }
-      const currentArtwork = artworkScore(m)
-      const representativeArtwork = artworkScore(g.rep)
-      if (currentArtwork > representativeArtwork) {
+      if (betterSeriesRepresentative(m, g.rep)) {
         g.rep = m
-      } else if (currentArtwork === representativeArtwork) {
-        const cur = (m.season_num ?? 0) * 10000 + (m.episode_num ?? 0)
-        const rep = (g.rep.season_num ?? 0) * 10000 + (g.rep.episode_num ?? 0)
-        if (cur > 0 && (rep === 0 || cur < rep)) g.rep = m
       }
     }
   }
   return Array.from(groups.values())
 }
 
+function betterSeriesRepresentative(candidate: Media, current: Media): boolean {
+  // A theatrical feature can have local poster/background artwork that scores
+  // higher than the TV poster. Keep the TV row as the series-card identity so
+  // the movie cannot replace the whole series title and overview.
+  const candidateTheatrical = isTheatricalFeature(candidate)
+  const currentTheatrical = isTheatricalFeature(current)
+  if (candidateTheatrical !== currentTheatrical) return !candidateTheatrical
+
+  const candidateArtwork = artworkScore(candidate)
+  const currentArtwork = artworkScore(current)
+  if (candidateArtwork !== currentArtwork) return candidateArtwork > currentArtwork
+
+  const cur = (candidate.season_num ?? 0) * 10000 + (candidate.episode_num ?? 0)
+  const rep = (current.season_num ?? 0) * 10000 + (current.episode_num ?? 0)
+  return cur > 0 && (rep === 0 || cur < rep)
+}
+
 function repeatedSeriesExternalRawKey(media: Media): string {
   if (!isEpisodeLike(media) && !pathLooksEpisodic(media)) return ''
   let identity = ''