diff --git a/$null b/$null
deleted file mode 100644
index ba3427b..0000000
--- a/$null
+++ /dev/null
@@ -1,2 +0,0 @@
-'Get-Content' is not recognized as an internal or external command,
-operable program or batch file.
diff --git a/internal/handler/emby_playback.go b/internal/handler/emby_playback.go
index 0450f7a..d9782ba 100644
--- a/internal/handler/emby_playback.go
+++ b/internal/handler/emby_playback.go
@@ -86,7 +86,9 @@ func embyPrewarmPlaybackTargets(svc *service.Container, c *gin.Context, out map[
 			if err != nil || m == nil {
 				return
 			}
-			raw := strings.TrimSpace(m.STRMURL)
+			// 与播放路径（StreamService.ServeFileWithCloudMode）同一套目标解析：
+			// STRMURL 为空时回读 .strm 文件内容，预热才能覆盖同一批条目。
+			raw := service.MediaSTRMTarget(m)
 			if raw == "" || !service.IsStrmMediaRow(m) {
 				return
 			}
@@ -409,9 +411,10 @@ func embyVideoHLSPlaylistHandler(svc *service.Container) gin.HandlerFunc {
 			c.Status(http.StatusNotFound)
 			return
 		}
-		uid := embyUserID(c)
-		item, err := svc.Emby.Item(c.Request.Context(), c.Param("id"), uid)
-		if err != nil || item == nil || svc.Stream == nil {
+		// 只需确认媒体行存在且对当前用户可见；Emby.Item 会构建完整条目载荷，
+		// 转码播放下每个分片请求都跑一遍太浪费。
+		m, err := svc.Repo.Media.FindByID(c.Request.Context(), c.Param("id"))
+		if err != nil || m == nil || !mediaVisibleForRequest(c, svc, m) || svc.Stream == nil {
 			c.Status(http.StatusNotFound)
 			return
 		}
@@ -436,9 +439,8 @@ func embyVideoHLSSegmentHandler(svc *service.Container) gin.HandlerFunc {
 			c.Status(http.StatusNotFound)
 			return
 		}
-		uid := embyUserID(c)
-		item, err := svc.Emby.Item(c.Request.Context(), c.Param("id"), uid)
-		if err != nil || item == nil || svc.Stream == nil {
+		m, err := svc.Repo.Media.FindByID(c.Request.Context(), c.Param("id"))
+		if err != nil || m == nil || !mediaVisibleForRequest(c, svc, m) || svc.Stream == nil {
 			c.Status(http.StatusNotFound)
 			return
 		}
diff --git a/internal/handler/playback_extra.go b/internal/handler/playback_extra.go
index 1ecdb2b..0c2c1df 100644
--- a/internal/handler/playback_extra.go
+++ b/internal/handler/playback_extra.go
@@ -12,6 +12,8 @@ import (
 	"net/url"
 	"strings"
 
+	"go.uber.org/zap"
+
 	"github.com/gin-gonic/gin"
 
 	"github.com/truewhile/MeBox/internal/middleware"
@@ -173,10 +175,20 @@ func externalPlaybackToken(c *gin.Context, svc *service.Container, mediaID strin
 	uid, _ := c.Get(middleware.CtxUserID)
 	u, err := svc.Repo.User.FindByID(c.Request.Context(), toString(uid))
 	if err != nil || u == nil {
+		if svc.Log != nil {
+			svc.Log.Warn("external playback token: user lookup failed",
+				zap.String("media_id", mediaID), zap.Error(err))
+		}
 		return ""
 	}
 	token, err := svc.Auth.IssueExternalPlaybackToken(u, mediaID, durationSec)
 	if err != nil {
+		// 静默返回空串会让 stream_url 变成 ?token=（空）、外部播放器只看到
+		// 401 无从排查，至少在服务端日志里留下原因。
+		if svc.Log != nil {
+			svc.Log.Warn("issue external playback token failed",
+				zap.String("media_id", mediaID), zap.Error(err))
+		}
 		return ""
 	}
 	return token
diff --git a/internal/service/cloud115_hls_proxy.go b/internal/service/cloud115_hls_proxy.go
index 626dea1..bce5fba 100644
--- a/internal/service/cloud115_hls_proxy.go
+++ b/internal/service/cloud115_hls_proxy.go
@@ -128,16 +128,16 @@ func (p *Cloud115HLSProxy) ServeChild(ctx context.Context, w http.ResponseWriter
 		strings.Contains(contentType, "application/vnd.apple.mpegurl")
 
 	if !isPlaylist {
+		// Content-Type 缺失时用前 4KB 内容嗅探是否为播放列表；无论结果如何
+		// 都要把已读前缀接回 body，避免分片/播放列表丢开头字节。
 		body, readErr := io.ReadAll(io.LimitReader(resp.Body, 4096))
 		if readErr != nil {
 			return readErr
 		}
 		if strings.HasPrefix(strings.TrimSpace(string(body)), "#EXTM3U") {
 			isPlaylist = true
-			resp.Body = io.NopCloser(io.MultiReader(strings.NewReader(string(body)), resp.Body))
-		} else {
-			resp.Body = io.NopCloser(io.MultiReader(strings.NewReader(string(body)), resp.Body))
 		}
+		resp.Body = io.NopCloser(io.MultiReader(strings.NewReader(string(body)), resp.Body))
 	}
 
 	copyUpstreamHeaders(w, resp, isPlaylist)
@@ -195,9 +195,17 @@ func (p *Cloud115HLSProxy) storeSession(session *cloud115HLSSession) {
 		}
 	}
 	if len(p.sessions) >= cloud115HLSMaxSessions {
-		for id := range p.sessions {
-			delete(p.sessions, id)
-			break
+		// ExpiresAt 恒为「最近一次活跃时间 + TTL」（lookup 会滑动续期），
+		// 因此最小者即最久未活跃的会话，淘汰它对正在播放的影响最小。
+		evictID := ""
+		var evictAt time.Time
+		for id, existing := range p.sessions {
+			if evictID == "" || existing.ExpiresAt.Before(evictAt) {
+				evictID, evictAt = id, existing.ExpiresAt
+			}
+		}
+		if evictID != "" {
+			delete(p.sessions, evictID)
 		}
 	}
 	session.ExpiresAt = now.Add(cloud115HLSSessionTTL)
@@ -210,9 +218,15 @@ func (p *Cloud115HLSProxy) lookup(sessionID, key string) (*cloud115HLSSession, s
 	}
 	p.mu.Lock()
 	session := p.sessions[sessionID]
-	if session != nil && time.Now().After(session.ExpiresAt) {
-		delete(p.sessions, sessionID)
-		session = nil
+	if session != nil {
+		if time.Now().After(session.ExpiresAt) {
+			delete(p.sessions, sessionID)
+			session = nil
+		} else {
+			// 滑动续期：VOD 点播整个播放期间只有分片请求，master 只在起播时取
+			// 一次，不续期的话会话会在 TTL 后被删，长视频播放到一半必然断流。
+			session.ExpiresAt = time.Now().Add(cloud115HLSSessionTTL)
+		}
 	}
 	p.mu.Unlock()
 	if session == nil {
diff --git a/internal/service/cloud115_hls_proxy_test.go b/internal/service/cloud115_hls_proxy_test.go
index 72225b1..1bfc3ba 100644
--- a/internal/service/cloud115_hls_proxy_test.go
+++ b/internal/service/cloud115_hls_proxy_test.go
@@ -3,6 +3,7 @@ package service
 import (
 	"bytes"
 	"context"
+	"fmt"
 	"io"
 	"net/http"
 	"net/http/httptest"
@@ -56,6 +57,67 @@ https://cpats01.115.com/seg.ts?x=1
 	}
 }
 
+// 长视频 VOD 播放期间只有分片请求经过 lookup，会话必须随活动滑动续期，
+// 否则固定 30 分钟 TTL 一到就会在中途 404 断流。
+func TestCloud115HLSProxyLookupRenewsSession(t *testing.T) {
+	proxy := &Cloud115HLSProxy{sessions: map[string]*cloud115HLSSession{}}
+	session := &cloud115HLSSession{
+		ID:      "sess",
+		MediaID: "media-1",
+		entries: map[string]string{"e1": "https://cpats01.115.com/v.m3u8"},
+	}
+	proxy.storeSession(session)
+	// 模拟播放进行到第 29 分钟：距过期只剩 1 分钟。
+	session.ExpiresAt = time.Now().Add(time.Minute)
+
+	if _, _, ok := proxy.lookup(session.ID, "e1"); !ok {
+		t.Fatal("active session should still resolve before expiry")
+	}
+	if remaining := time.Until(session.ExpiresAt); remaining < cloud115HLSSessionTTL-10*time.Second {
+		t.Fatalf("session not renewed on activity, remaining = %v", remaining)
+	}
+
+	// 真正过期（期间无任何活动）的会话仍要被清理。
+	session.ExpiresAt = time.Now().Add(-time.Minute)
+	if _, _, ok := proxy.lookup(session.ID, "e1"); ok {
+		t.Fatal("expired session should not resolve")
+	}
+	proxy.mu.Lock()
+	_, exists := proxy.sessions[session.ID]
+	proxy.mu.Unlock()
+	if exists {
+		t.Fatal("expired session should be evicted from the map")
+	}
+}
+
+// 满员驱逐必须淘汰最久未活跃的会话（ExpiresAt = 最近活跃 + TTL，最小者即
+// 最久未活跃），而不是随机挑一个——随机驱逐可能正好杀掉正在播放的会话。
+func TestCloud115HLSProxyEvictsLeastRecentlyActiveSession(t *testing.T) {
+	proxy := &Cloud115HLSProxy{sessions: map[string]*cloud115HLSSession{}}
+	first := &cloud115HLSSession{ID: "active", MediaID: "media-1", entries: map[string]string{}}
+	proxy.storeSession(first)
+	for i := 0; i < cloud115HLSMaxSessions-1; i++ {
+		proxy.storeSession(&cloud115HLSSession{ID: fmt.Sprintf("s-%03d", i), MediaID: "media-1", entries: map[string]string{}})
+	}
+	// 人为拉开活跃时间差，避免依赖时钟精度：active 最近活跃，s-000 最久未活跃。
+	base := time.Now()
+	first.ExpiresAt = base.Add(cloud115HLSSessionTTL)
+	proxy.sessions["s-000"].ExpiresAt = base.Add(cloud115HLSSessionTTL - time.Hour)
+
+	proxy.storeSession(&cloud115HLSSession{ID: "newcomer", MediaID: "media-1", entries: map[string]string{}})
+
+	proxy.mu.Lock()
+	_, activeExists := proxy.sessions["active"]
+	_, staleExists := proxy.sessions["s-000"]
+	proxy.mu.Unlock()
+	if !activeExists {
+		t.Fatal("recently active session must survive eviction")
+	}
+	if staleExists {
+		t.Fatal("least recently active session should have been evicted")
+	}
+}
+
 func TestIsAllowed115UpstreamHost(t *testing.T) {
 	for _, host := range []string{"videoplay.115.com", "cpats01.115.com", "cdn.115cdn.net"} {
 		if !isAllowed115UpstreamHost(host) {
diff --git a/internal/service/cloud115_playback.go b/internal/service/cloud115_playback.go
index 7923f12..af5834e 100644
--- a/internal/service/cloud115_playback.go
+++ b/internal/service/cloud115_playback.go
@@ -220,6 +220,11 @@ func (s *Cloud115PlaybackService) ResolveCloud115URL(ctx context.Context, mediaI
 	return strings.TrimSpace(item.URL), data, nil
 }
 
+// cloud115PushStateRetention pushState 条目保留上限。成功条目 3 小时内用于
+// 去重；超过一倍余量即为死数据，触发转码请求时顺带清理，防止 map 随观看过的
+// 条目数无限增长。
+const cloud115PushStateRetention = 6 * time.Hour
+
 func (s *Cloud115PlaybackService) ensureCloudTranscode(
 	ctx context.Context,
 	accountID, pickCode string,
@@ -230,6 +235,13 @@ func (s *Cloud115PlaybackService) ensureCloudTranscode(
 	now := time.Now()
 
 	s.mu.Lock()
+	if len(s.pushState) > 0 {
+		for k, v := range s.pushState {
+			if now.Sub(v.at) > cloud115PushStateRetention {
+				delete(s.pushState, k)
+			}
+		}
+	}
 	if last, ok := s.pushState[key]; ok {
 		ttl := 2 * time.Minute
 		if last.success {
diff --git a/internal/service/stream_file.go b/internal/service/stream_file.go
index 570c904..a91ea18 100644
--- a/internal/service/stream_file.go
+++ b/internal/service/stream_file.go
@@ -22,6 +22,25 @@ func (s *StreamService) ServeFile(w http.ResponseWriter, r *http.Request, mediaI
 	return s.ServeFileWithCloudMode(w, r, mediaID, "")
 }
 
+// MediaSTRMTarget 返回媒体行固化的 STRM 播放目标。STRMURL 为空时回读本地
+// .strm 文件内容兜底（扫描时内容解析失败的行只剩 Container=strm + Path），
+// 仍拿不到返回空串。
+func MediaSTRMTarget(m *model.Media) string {
+	if m == nil {
+		return ""
+	}
+	if raw := strings.TrimSpace(m.STRMURL); raw != "" {
+		return raw
+	}
+	path := strings.TrimSpace(m.Path)
+	if strings.HasSuffix(strings.ToLower(path), ".strm") {
+		if target, err := readLocalSTRMTarget(path); err == nil {
+			return strings.TrimSpace(target)
+		}
+	}
+	return ""
+}
+
 func (s *StreamService) ServeFileWithCloudMode(w http.ResponseWriter, r *http.Request, mediaID, cloudMode string) error {
 	m, err := s.repo.Media.FindByID(r.Context(), mediaID)
 	if err != nil {
@@ -30,7 +49,8 @@ func (s *StreamService) ServeFileWithCloudMode(w http.ResponseWriter, r *http.Re
 	if m == nil {
 		return ErrMediaNotFound
 	}
-	if strmURL := strings.TrimSpace(m.STRMURL); strmURL != "" && playableSTRMTarget(r.Context(), s.repo, strmURL, m) {
+	strmURL := MediaSTRMTarget(m)
+	if strmURL != "" && playableSTRMTarget(r.Context(), s.repo, strmURL, m) {
 		if !cloudPlaybackModeEnabled(r.Context(), s.repo, cloudMode) {
 			return ErrCloudPlaybackDisabled
 		}
@@ -50,10 +70,14 @@ func (s *StreamService) ServeFileWithCloudMode(w http.ResponseWriter, r *http.Re
 		http.Redirect(w, r, absoluteInternalRedirect(target, r), http.StatusFound)
 		return nil
 	}
-	if strings.HasPrefix(strings.ToLower(strings.TrimSpace(m.Path)), "cloud://") {
-		// 云盘媒体没有本地文件可回退；走到这里说明 STRM 播放被关闭或
-		// STRMURL 缺失。返回明确错误而不是笼统的「文件不存在」，
-		// 处理器据此回 502 + 原因，方便用户在播放器/日志里定位。
+	pathLower := strings.ToLower(strings.TrimSpace(m.Path))
+	if strings.HasPrefix(pathLower, "cloud://") ||
+		strings.HasSuffix(pathLower, ".strm") ||
+		strings.EqualFold(strings.TrimSpace(m.Container), "strm") {
+		// 云盘/STRM 媒体没有本地视频文件可回退；走到这里说明 STRM 播放被关闭
+		// 或播放目标缺失（.strm 内容解析失败）。绝不能把 .strm 文本文件当视频
+		// 流出去，返回明确错误而不是笼统的「文件不存在」，处理器据此回
+		// 502 + 原因，方便用户在播放器/日志里定位。
 		return ErrCloudPlaybackUnavailable
 	}
 	f, err := os.Open(m.Path)
diff --git a/internal/service/stream_test.go b/internal/service/stream_test.go
index 0e20d31..6edbf03 100644
--- a/internal/service/stream_test.go
+++ b/internal/service/stream_test.go
@@ -5,6 +5,8 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"net/url"
+	"os"
+	"path/filepath"
 	"strings"
 	"testing"
 
@@ -251,6 +253,72 @@ func TestServeFilePassesThroughForeignInstanceSTRMURL(t *testing.T) {
 
 // 本机自己生成的 .strm 在换了域名/IP 之后仍要认领：host 对不上，但 acct 是本机
 // 网盘账号，于是按当前请求 host 相对化，保持可播放。
+// 扫描时 .strm 内容解析失败会产生 Container=strm 但 STRMURL 为空的行：
+// 播放路径必须回读 .strm 文件内容兜底（与 MediaPlaybackProvider 等一致），
+// 而不是把 .strm 文本文件当视频流返回。
+func TestServeFileFallsBackToStrmFileContentWhenSTRMURLEmpty(t *testing.T) {
+	repos := newStreamTestRepo(t)
+	dir := t.TempDir()
+	strmPath := filepath.Join(dir, "Movie.strm")
+	target := "https://cdn.example.test/Movie.mkv?sign=direct"
+	if err := os.WriteFile(strmPath, []byte(target+"\n"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	if err := repos.DB.Create(&model.Media{
+		Base:      model.Base{ID: "strm-empty-url"},
+		Title:     "STRM Empty URL",
+		Path:      strmPath,
+		Container: "strm",
+		STRMURL:   "",
+	}).Error; err != nil {
+		t.Fatal(err)
+	}
+	svc := NewStreamService(&config.Config{}, zap.NewNop(), repos, nil)
+	req := httptest.NewRequest(http.MethodGet, "http://nas.local:18080/api/stream/strm-empty-url?token=jwt123", nil)
+	w := httptest.NewRecorder()
+
+	if err := svc.ServeFile(w, req, "strm-empty-url"); err != nil {
+		t.Fatalf("empty-STRMURL .strm row should fall back to file content: %v", err)
+	}
+	if w.Code != http.StatusFound {
+		t.Fatalf("status = %d, want 302", w.Code)
+	}
+	if loc := w.Header().Get("Location"); loc != target {
+		t.Fatalf("Location = %q, want %q", loc, target)
+	}
+}
+
+// .strm 内容完全解析不出播放目标时，返回明确的 502 错误，绝不把 .strm 文本
+// 文件本身当视频流吐给播放器。
+func TestServeFileRejectsStrmRowWithUnresolvableTarget(t *testing.T) {
+	repos := newStreamTestRepo(t)
+	dir := t.TempDir()
+	strmPath := filepath.Join(dir, "Broken.strm")
+	if err := os.WriteFile(strmPath, []byte("# 只有注释，没有可用播放地址\n"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	if err := repos.DB.Create(&model.Media{
+		Base:      model.Base{ID: "strm-broken"},
+		Title:     "STRM Broken",
+		Path:      strmPath,
+		Container: "strm",
+		STRMURL:   "",
+	}).Error; err != nil {
+		t.Fatal(err)
+	}
+	svc := NewStreamService(&config.Config{}, zap.NewNop(), repos, nil)
+	req := httptest.NewRequest(http.MethodGet, "http://nas.local:18080/api/stream/strm-broken", nil)
+	w := httptest.NewRecorder()
+
+	err := svc.ServeFile(w, req, "strm-broken")
+	if !errors.Is(err, ErrCloudPlaybackUnavailable) {
+		t.Fatalf("error = %v, want ErrCloudPlaybackUnavailable", err)
+	}
+	if w.Code != http.StatusOK {
+		t.Fatalf("no bytes should be written on error, status = %d", w.Code)
+	}
+}
+
 func TestServeFileRealignsOwnSTRMURLOtherHost(t *testing.T) {
 	repos := repository.New(newServiceTestDB(t, &model.Media{}, &model.Setting{}, &model.StrmAccount{}))
 	if err := repos.StrmAccount.Create(t.Context(), &model.StrmAccount{
diff --git a/internal/service/strm_play.go b/internal/service/strm_play.go
index 2b3952e..e615514 100644
--- a/internal/service/strm_play.go
+++ b/internal/service/strm_play.go
@@ -286,7 +286,7 @@ func (s *StrmService) ProxyDirect(ctx context.Context, w http.ResponseWriter, r
 			req.Header.Set("User-Agent", ua)
 		}
 	}
-	resp, err := s.http.Do(req)
+	resp, err := s.streamHTTP.Do(req)
 	if err != nil {
 		return err
 	}
diff --git a/internal/service/strm_service.go b/internal/service/strm_service.go
index 94054f2..9108409 100644
--- a/internal/service/strm_service.go
+++ b/internal/service/strm_service.go
@@ -11,6 +11,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"net"
 	"net/http"
 	"os"
 	"path/filepath"
@@ -81,14 +82,15 @@ var StrmAccountSecretKeys = []string{"cookie", "password", "token", "access_toke
 
 // StrmService 提供 STRM 管理的能力。
 type StrmService struct {
-	log      *zap.Logger
-	repo     *repository.Container
-	cfg      *config.Config
-	crypto   *CryptoService
-	http     *http.Client
-	stopOnce sync.Once
-	stopCh   chan struct{}
-	baseCtx  context.Context // 服务级长期上下文（同步/队列不随 HTTP 请求取消）
+	log        *zap.Logger
+	repo       *repository.Container
+	cfg        *config.Config
+	crypto     *CryptoService
+	http       *http.Client
+	streamHTTP *http.Client // 视频流转发专用：无总超时（见 ProxyDirect）
+	stopOnce   sync.Once
+	stopCh     chan struct{}
+	baseCtx    context.Context // 服务级长期上下文（同步/队列不随 HTTP 请求取消）
 
 	mu            sync.Mutex
 	running       map[string]context.CancelFunc // sync path id -> cancel
@@ -161,11 +163,24 @@ func (s *StrmService) releaseDownloadSlot(provider string) {
 // NewStrmService constructs the STRM service.
 func NewStrmService(cfg *config.Config, log *zap.Logger, repos *repository.Container, crypto *CryptoService) *StrmService {
 	return &StrmService{
-		log:              log,
-		repo:             repos,
-		cfg:              cfg,
-		crypto:           crypto,
-		http:             &http.Client{Timeout: 90 * time.Second},
+		log:    log,
+		repo:   repos,
+		cfg:    cfg,
+		crypto: crypto,
+		http:   &http.Client{Timeout: 90 * time.Second},
+		// 视频流转发不能用带总超时的 client：http.Client.Timeout 覆盖整个
+		// 响应体读取，长视频必然超过 90s 被硬切。传输生命周期由请求 ctx
+		// （客户端断开即取消）控制，这里只保留建连/响应头阶段的兜底超时。
+		streamHTTP: &http.Client{
+			Transport: &http.Transport{
+				Proxy:                 http.ProxyFromEnvironment,
+				DialContext:           (&net.Dialer{Timeout: 15 * time.Second, KeepAlive: 30 * time.Second}).DialContext,
+				ForceAttemptHTTP2:     true,
+				TLSHandshakeTimeout:   10 * time.Second,
+				ResponseHeaderTimeout: 30 * time.Second,
+				IdleConnTimeout:       90 * time.Second,
+			},
+		},
 		stopCh:           make(chan struct{}),
 		baseCtx:          context.Background(),
 		running:          map[string]context.CancelFunc{},