feat(subtitles): optimize anime stream audio extraction

- Prefer matching audio and lower-resolution sources with HLS sampling
- Reuse verified audio within sessions and clean temporary files on shutdown
- Allow character dictionary sync without loaded subtitles

changes/anime-browser-disclaimer-docs.md

@@ -0,0 +1,4 @@
+type: docs
+area: anime
+
+- Added a README disclaimer stating that SubMiner hosts no content, ships no anime sources or repositories, is not affiliated with any content provider, and that users are responsible for the content they access. The anime browser docs no longer describe SubMiner as a "host" of extensions.

changes/anime-stream-subtitle-generation-docs.md

@@ -1,4 +1,5 @@
 type: docs
 area: subtitles
 
-- Document anime stream generation, cache locations, full-episode processing, supported audio tracks, and stream access limitations.
+- Document anime stream generation, audio-only and lower-resolution extraction candidates, concurrent HLS downloads, temporary disk usage, audio cache reuse and limits, full-episode processing, supported audio tracks, and stream access limitations.
+- Explain HLS source-check diagnostics and session-only audio cleanup on quit and after crashes.

changes/anime-stream-subtitle-generation.md

@@ -2,3 +2,5 @@ type: added
 area: subtitles
 
 - Generate Japanese subtitles from finite HTTP/HTTPS anime episode streams in the existing generation modal. Reuse mpv's supported request headers and the anime proxy, transcribe downloaded audio locally, retain generated SRT files in the application cache, and load them only into the matching stream. Local-file generation and the launcher keep their existing behavior.
+- Prepare plain HLS episodes with up to four concurrent segment downloads, preserving audio order and timing. Show download progress, cancel active requests together, and retain FFmpeg extraction for complex playlists.
+- Reduce anime-stream extraction downloads by preferring separate Japanese audio or lower-resolution video when duration and sampled audio match playback. Sample HLS through short local segment windows, account for timestamp origins, retry empty original samples, and report why candidates are rejected. Selected external HTTP audio tracks are extracted directly with their playback delay preserved. Reuse verified completed audio across transcription retries and model changes within the current app session. Remove downloaded audio and working files on quit, recover abandoned sessions on startup, and preserve saved subtitles.

changes/character-dictionary-without-subtitles-docs.md

@@ -0,0 +1,4 @@
+type: docs
+area: subtitles
+
+- Clarify that character dictionary sync works without a subtitle track and explain readiness and import timeouts.

changes/character-dictionary-without-subtitles.md

@@ -0,0 +1,4 @@
+type: fixed
+area: subtitles
+
+- Let character dictionaries finish syncing when no Japanese subtitles are loaded. Wait for Yomitan extension readiness instead of the first processed subtitle, and report readiness failures instead of leaving the notification stuck on Checking.