fix: delete yt-dlp partial files when it fails (v1.0.0.14)

yt-dlp removes its separate video/audio files after a successful merge, but
a failed run (e.g. HTTP 403 mid-download) left "<name>.f137.mp4.part" etc.
in the trailer folder, even when the built-in fallback then succeeded.
Always remove files sharing the output's "<name>." prefix after yt-dlp runs.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

build.yaml

@@ -1,5 +1,5 @@
 ---
-version: 1.0.0.13
+version: 1.0.0.14
 name: CinemaTrailers4Jellyfins
 guid: b581493e-1046-40ed-b6dc-cb8027624984
 description: >
@@ -12,12 +12,9 @@ category: General
 owner: 514mart
 targetAbi: 10.11.0.0
 changelog:
-  - yt-dlp now prefers H.264 + AAC (plays or hardware-transcodes on every
-    client; VP9/AV1 often needed a CPU transcode) and uses Jellyfin's own
-    ffmpeg for the merge
-  - If yt-dlp fails, the built-in downloader is tried instead
-  - Fix a possible hang. yt-dlp's output is now read while it runs, so a
-    full output buffer can no longer block it
+  - When yt-dlp fails part-way, its partial download files (.part, .ytdl,
+    separate video/audio) are now deleted instead of being left in the
+    trailer folder
 
 dotnetProjects:
   - name: Jellyfin.Plugin.CinemaTrailers4Jellyfins