Switch to web_embedded player client

web_embedded: supports cookies, no Node.js/JS runtime needed, 23 video
formats available. android_vr was skipped by yt-dlp when cookies are
present since that client doesn't support cookie auth.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/routers/settings.py

@@ -247,7 +247,7 @@ def ytdlp_test(
             "yt-dlp",
             "https://www.youtube.com/watch?v=dQw4w9WgXcQ",
             "--dump-json", "--no-download", "--no-playlist",
-            "--extractor-args", "youtube:player_client=android_vr",
+            "--extractor-args", "youtube:player_client=web_embedded",
             *cookie_args,
         ],
         capture_output=True, text=True, timeout=30,

backend/services/ytdlp.py

@@ -216,7 +216,7 @@ def fetch_video_metadata(video_id: str) -> dict | None:
     base_cmd = [
         "yt-dlp", url,
         "--dump-json", "--no-download", "--no-playlist",
-        "--extractor-args", "youtube:player_client=android_vr",
+        "--extractor-args", "youtube:player_client=web_embedded",
     ]
     stdout, stderr, code = _run([*base_cmd, *cookie_args], timeout=30)
     if code != 0:
@@ -567,7 +567,7 @@ def start_download(
                     "--no-part", "--no-mtime",
                     "-o", output_template,
                     "--newline", "--progress", "--no-colors",
-                    "--extractor-args", "youtube:player_client=android_vr",
+                    "--extractor-args", "youtube:player_client=web_embedded",
                     *cookie_args,
                 ],
                 stdout=subprocess.PIPE,