feat(strm): 同名多版本择优 / keep_ext，并支持合并展示与播放切换 (#30)

* feat(strm): 同名多版本择优/keep_ext，并支持合并展示与播放切换

默认对同名不同扩展（如 .mkv/.mp4）按体积→mtime→扩展名优先级择优生成一条 strm，冲突打日志；开启 keep_ext 则分别生成 name.ext.strm。媒体详情与播放器可切换版本，列表继续合并同片多版本，Emby MediaSources 名称区分容器/分辨率。

Co-authored-by: truewhile <truewhile@users.noreply.github.com>

* fix(meta): 边车匹配忽略 .mkv.strm 中间扩展，同片共享 NFO/海报/字幕

NFO、海报、字幕与刮削写出统一使用 mediaSidecarBase 词干，使竞女01.mkv.strm
与竞女01.mp4.strm 配对同一套 竞女01.nfo / 竞女01-poster / 竞女01.srt；
仍兼容历史上的 name.mkv.nfo 命名。

Co-authored-by: truewhile <truewhile@users.noreply.github.com>

* fix(emby): People NFO 按共享词干匹配 keep_ext strm

resolveMediaPeople 改为查找竞女01.nfo（并兼容旧的竞女01.mkv.nfo），
同时修正把 decodeNFOFile 的 partial 误当 ok 导致完整 NFO 被跳过的问题。

Co-authored-by: truewhile <truewhile@users.noreply.github.com>

---------

Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: truewhile <truewhile@users.noreply.github.com>

web/src/pages/PlayerPage.tsx

@@ -18,6 +18,8 @@ import { PlayerTopBar } from './PlayerTopBar'
 import { PlayerVideoStage } from './PlayerVideoStage'
 import { PlayerDanmakuPanel } from '../components/PlayerDanmakuPanel'
 import { PlayerPlaylistPanel } from '../components/PlayerPlaylistPanel'
+import { MediaVersionSwitcher } from '../components/MediaVersionSwitcher'
+import { mediaVersionsOf } from '../utils/mediaVersion'
 
 // Fullscreen, dark-themed video page.
 //
@@ -420,6 +422,15 @@ export function PlayerPage() {
     [navigate, location.search, location.state],
   )
 
+  const versionList = useMemo(() => mediaVersionsOf(media), [media])
+  const switchVersion = useCallback(
+    (version: Media) => {
+      if (!version?.id || version.id === media?.id) return
+      playEpisode(version)
+    },
+    [media?.id, playEpisode],
+  )
+
   const handlePrevEpisode = useCallback(() => {
     if (prevEpisode) {
       playEpisode(prevEpisode)
@@ -575,6 +586,13 @@ export function PlayerPage() {
         onBack={goBack}
         onToggleMode={toggleMode}
       />
+      {versionList.length > 1 && (
+        <div className="pointer-events-none absolute inset-x-0 top-16 z-20 flex justify-center px-4 sm:top-20">
+          <div className="pointer-events-auto max-w-3xl rounded-2xl border border-white/15 bg-black/70 px-3 py-2 shadow-xl backdrop-blur">
+            <MediaVersionSwitcher media={media!} mode="player" onSelect={switchVersion} className="text-white" />
+          </div>
+        </div>
+      )}
       <PlayerVideoStage
         media={media}
         loadError={loadError}