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/index.html

@@ -148,6 +148,10 @@
                 <span>Title</span>
                 <input id="tsukihimeTitle" type="text" placeholder="Anime title" />
               </label>
+              <label class="jimaku-field">
+                <span>Season</span>
+                <input id="tsukihimeSeason" type="number" min="1" placeholder="1" />
+              </label>
               <label class="jimaku-field">
                 <span>Episode</span>
                 <input id="tsukihimeEpisode" type="number" min="1" placeholder="1" />