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

src/animeui/animeui.ts

@@ -333,6 +333,7 @@ async function playEpisode(button: HTMLButtonElement, episode: AnimeBrowserEpiso
     animeTitle: selectedAnime.title,
     episodeUrl: episode.url,
     episodeName: episode.name,
+    episodeNumber: episode.number,
   });
 
   if (result.ok) {