fix(xtream): try advertised TS after initial web HLS HTTP failure (#1558)

* fix(xtream): try advertised TS after initial web HLS HTTP failure

* refactor(playback): extract fullscreen channel panel state

* test(xtream): keep synthetic media within the mock project

CLAUDE.md

@@ -782,6 +782,18 @@ categories by provider ID and type. See `docs/architecture/category-management.m
 
 ### Key Features
 
+#### Xtream Live Auto Format
+
+The routed Xtream live host supplies `liveAutoTsUrl` only for Auto with explicit
+HLS+TS account evidence, using the canonical URL builder and original headers.
+The same web player may try TS once after an owned initial terminal HTTP failure,
+before `playing`; the old transport unmounts before the guarded render callback
+starts TS. No player preference or playlist cache changes. Manual formats,
+unknown formats, DRM, VOD/catch-up and stale sessions are excluded. External
+MPV/VLC and Embedded MPV retain manual TS; Video.js segment retry cycles without
+a terminal diagnostic also need manual TS. Contract and full support matrix:
+`docs/architecture/xtream-portal-compatibility.md` (Initial Auto HLS failure).
+
 #### M3U URL User-Agent
 
 - The URL import form accepts an optional User-Agent and stores it as