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>

internal/service/organizer_directory_versions.go

@@ -278,16 +278,21 @@ func randomSuffix() string {
 // moveStagedArtwork renames artwork sidecars staged alongside `stage` into
 // their final names next to `dst`.
 func moveStagedArtwork(stage, dst string) {
-	stageBase := strings.TrimSuffix(filepath.Base(stage), filepath.Ext(stage))
-	dstBase := strings.TrimSuffix(filepath.Base(dst), filepath.Ext(dst))
+	stageBases := mediaSidecarBaseVariants(stage)
+	dstBase := mediaSidecarBase(dst)
+	if dstBase == "" {
+		dstBase = strings.TrimSuffix(filepath.Base(dst), filepath.Ext(dst))
+	}
 	stageDir := filepath.Dir(stage)
-	for _, suffix := range artworkSidecarSuffixes {
-		for _, ext := range artworkSidecarExtensions {
-			srcPath := filepath.Join(stageDir, stageBase+suffix+ext)
-			if _, err := os.Stat(srcPath); err != nil {
-				continue
+	for _, stageBase := range stageBases {
+		for _, suffix := range artworkSidecarSuffixes {
+			for _, ext := range artworkSidecarExtensions {
+				srcPath := filepath.Join(stageDir, stageBase+suffix+ext)
+				if _, err := os.Stat(srcPath); err != nil {
+					continue
+				}
+				_ = os.Rename(srcPath, filepath.Join(stageDir, dstBase+suffix+ext))
 			}
-			_ = os.Rename(srcPath, filepath.Join(stageDir, dstBase+suffix+ext))
 		}
 	}
 }
@@ -306,12 +311,13 @@ func moveSidecarRename(from, to string) {
 // removeStagedArtwork removes artwork sidecars that were staged alongside
 // `stage`, used when a replace fails and its staged outputs must be cleaned up.
 func removeStagedArtwork(stage string) {
-	stageBase := strings.TrimSuffix(filepath.Base(stage), filepath.Ext(stage))
+	stageBases := mediaSidecarBaseVariants(stage)
 	stageDir := filepath.Dir(stage)
-	for _, suffix := range artworkSidecarSuffixes {
-		for _, ext := range artworkSidecarExtensions {
-			path := filepath.Join(stageDir, stageBase+suffix+ext)
-			_ = os.Remove(path)
+	for _, stageBase := range stageBases {
+		for _, suffix := range artworkSidecarSuffixes {
+			for _, ext := range artworkSidecarExtensions {
+				_ = os.Remove(filepath.Join(stageDir, stageBase+suffix+ext))
+			}
 		}
 	}
 }