fix(anime): thread episode metadata through stream playback and fix seas

- Split anime browser stream titles into series/season/episode fields (episode-metadata.ts) instead of one joined string, so stats grouping, the mpv title, and the Jimaku/TsukiHime modals all get real values instead of a filename-derived "m3u8"
- Fix AniList season resolver to walk through split-cour sequels and specials without counting them as a season, and to surface rate-limit/network failures instead of falling through to a wrong air-order guess
- Add a Season field to the TsukiHime modal and include later seasons in its search query
- Rewrite WebVTT subtitle tracks as SRT before handing them to alass, since alass has no VTT support and streams serve VTT
- Update CHANGELOG and troubleshooting docs

CHANGELOG.md

@@ -12,7 +12,14 @@
 
 ### Fixed
 
+- Split-Cour Season Resolution: Resolving "season N" against AniList no longer lands one season short for franchises whose broadcast seasons are listed as several entries. AniList records the back half of a split cour ("… Season 2 Part 2", "… Cour 2", "第2クール") as its own sequel, and the resolver counted each as a season — so Mushoku Tensei season 3 resolved to the season 2 entry and Re:ZERO season 4 to season 3, which then drove the character dictionary and AniList progress updates to the wrong series. A sequel carrying a part or cour marker that matches the season it continues is now followed without advancing the season count, in both the relation walk and the air-order fallback. Titles are compared ignoring punctuation, since AniList spells the same name inconsistently across a franchise's own entries, and the marker is looked for in every title and synonym rather than just the display title. Note that a wrong match cached before this fix is remembered in `character-dictionaries/anilist-resolution-cache.json` and needs to be removed (or overridden from the character dictionary picker) for the affected series.
+- Specials In The Season Chain: A special or OVA sitting in a franchise's sequel chain is now walked through without counting as a season. Dr. STONE links STONE WARS to New World through a one-episode special, which made New World resolve as season 4 and every later season shift with it.
+- Season Resolution Under Rate Limiting: An AniList rate limit or network failure while walking sequel relations is now reported so the caller can retry, instead of falling through to the air-date fallback. That fallback is for a franchise with missing relation edges; running it after a failed lookup turned a transient 429 into a confidently wrong season.
+- Anime Browser Titles: An episode launched from the anime browser now carries its series, season and episode number through the app instead of a single joined string. Stats groups streams by series (every stream previously landed in one entry named `m3u8`, because the only readable part of the strip-proxy URL was its file extension), rewatching an episode reuses its entry rather than creating a new one, the Jimaku and TsukiHime modals prefill Title/Season/Episode from the source's own listing instead of leaving them blank, and AniList updates use those fields directly. The mpv title now reads `Series S03E04 - Episode Name`.
+- TsukiHime Season: The TsukiHime modal has a Season field, matching Jimaku. It is filled in automatically for anime browser streams, and seasons after the first are included in the search query so a later season's releases are actually found.
+- Episode Parsing: The shared title parser now recognizes spelled-out episode labels (`Episode 4`, `第4話`) and a season named in the title (`… Season 3`, `… 2nd Season`, `… S3`), which are put in the Season field instead of being searched for as part of the series name.
 - Subtitle Sync On Streams: Subsync now works when mpv loaded a subtitle track from a URL, which is how Aniyomi extension streams and Jellyfin add theirs. Such a track is downloaded to a temporary file first — reusing mpv's own request headers, so authenticated and referer-gated hosts stay reachable — instead of being rejected with "Subtitle file not found: https://…". This applies to both the sync target and the alass reference, so a Jimaku or TsukiHime download can now be retimed against a stream's own subtitles. Internal tracks of a stream also pass mpv's headers through to `ffmpeg`.
+- Subsync With WebVTT Tracks: Alass now works on tracks that arrive as WebVTT, which is what Aniyomi extension streams serve. Alass picks its parser from the file extension and has no WebVTT support, so it treated a `.vtt` reference as a video file and failed with "no audio stream in file" (and a VTT saved under an `.srt` name died in its SubRip parser instead). Both the sync target and the reference are now rewritten as SRT for alass, keeping the cue text as-is, and the originals are left untouched.
 - Subsync Tool Discovery: Leaving `subsync.alass_path`, `ffsubsync_path`, or `ffmpeg_path` empty now actually auto-discovers the binary, as the config help has always claimed. Previously it fell back to a hard-coded `/usr/bin/<tool>`, which does not exist on macOS and broke subsync for every default-config install there. Discovery searches `PATH` plus the usual install prefixes (a GUI launch inherits a minimal `PATH`) and accepts `alass-cli` as well as `alass`. An explicitly configured path is still used verbatim and never silently substituted.
 - Subsync Logging: Subsync failures are now written to the application log. Previously the only trace was an OSD toast that vanished after a few seconds, leaving nothing to diagnose from.
 - Anime Browser Window Switching: Opening the anime browser now shows a tray icon on every platform and — on macOS — puts the app in the Cmd+Tab switcher (which requires the Dock icon; the two are inseparable on macOS), so you can switch between it and mpv. Previously the subtitle overlay's fullscreen support hid the whole app from the Dock and Cmd+Tab, leaving no way to reach the window. The Dock icon is released again when the window closes during playback.