feat(catchup): launch past Guide programmes through service-owned playback intent

[MrFr3di]

Refs #305, parent #184. Follows merged #304.

Implements the bounded Guide → service-owned catch-up launch slice while preserving the existing player/recovery/seek authorities.

Implemented through TDD Tasks 1–6:

• PlaybackStartRequest carries provider-neutral PlaybackIntent with legacy Live source compatibility;
• Media3 session Bundle codec preserves semantic Live/CatchupProgram/CatchupPosition fields only;
• service recovery resolves intent for the exact candidate selected by the existing bounded recovery loop;
• RoomPlaybackCatalog supplies persisted M3U archive resolution without a Room schema change;
• Guide keeps original EPG bounds separate from clipped viewport geometry and maps status/current → Live, completed → CatchupProgram, future → no launch;
• navigation stores only a bounded programme identity/start/end tuple and reconstructs PlaybackIntent at Player entry;
• Player forwards the semantic intent into the existing service command; favorite, LAN permission and exact-origin cleartext approval remain channel/final-transport behavior.

Current exact head: f7d9a3d3e4386add722362225db83fbb41e9acba.

Task 6 clean RED was observed at 513e296ff4f40da902ee564c049db5a81bfb6b00: all non-hosted gates passed and Hosted validation failed specifically at :feature:player:compileDebugUnitTestKotlin because playerPlaybackStartRequest was intentionally absent. Task 6 GREEN is now on the exact head above.

No Xtream catch-up, local timeshift/DVR/VOD, new provider framework, Room migration, new player/retry/seek owner, buffer tuning, or third persistent AVD is included.

Merge remains blocked until every required exact-head gate is terminal GREEN.