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/renderer/utils/dom.ts

@@ -24,6 +24,7 @@ export type RendererDom = {
 
   tsukihimeModal: HTMLDivElement;
   tsukihimeTitleInput: HTMLInputElement;
+  tsukihimeSeasonInput: HTMLInputElement;
   tsukihimeEpisodeInput: HTMLInputElement;
   tsukihimeSearchButton: HTMLButtonElement;
   tsukihimeCloseButton: HTMLButtonElement;
@@ -180,6 +181,7 @@ export function resolveRendererDom(): RendererDom {
 
     tsukihimeModal: getRequiredElement<HTMLDivElement>('tsukihimeModal'),
     tsukihimeTitleInput: getRequiredElement<HTMLInputElement>('tsukihimeTitle'),
+    tsukihimeSeasonInput: getRequiredElement<HTMLInputElement>('tsukihimeSeason'),
     tsukihimeEpisodeInput: getRequiredElement<HTMLInputElement>('tsukihimeEpisode'),
     tsukihimeSearchButton: getRequiredElement<HTMLButtonElement>('tsukihimeSearch'),
     tsukihimeCloseButton: getRequiredElement<HTMLButtonElement>('tsukihimeClose'),