feat(catchup): resolve Xtream archive through existing playback intent

[MrFr3di]

Refs #315, parent #184.

Completes the bounded Xtream catch-up slice through the existing provider-neutral playback architecture; no second catch-up framework, player path, provider registry, or Room schema change.

Implemented:

• persists supported tv_archive / tv_archive_duration through the existing generic catch-up metadata;
• resolves accepted CatchupProgram intents into an opaque Xtream archive reference plus the existing ResolvedPlaybackTimeline contract;
• materializes that opaque reference through XtreamPlaybackReferenceResolver using the existing credential lookup, SourceUrlPolicy, exact HTTP approval and redaction ownership;
• supports only the evidence-backed first dialect /timeshift/{username}/{password}/{duration}/{start}/{streamId}.{ext}, with duration in minutes and UTC start formatted yyyy-MM-dd:HH-mm;
• composes Xtream first with fallback to the existing M3U archive resolver only on NotApplicable;
• marks the characterized Xtream archive semantics SUPPORTED in the compatibility corpus without claiming alternate timeshift dialects.

TDD evidence includes separate RED/GREEN checkpoints for metadata persistence, archive intent resolution, transport materialization, and M3U+Xtream application composition. Composition RED: a50e0a4673fd93a9203d65afaa343549d51be22f; production composition: b0aad3230bd3011e32f69867fee10b82051ccb34.

Final exact head cee85003f38637b28b0e2169ce725db7196726b4 is ahead 10 / behind 0 against main 22011085b52179c33661c8fc11e37137785d3a02 and passed:

• Hosted validation #2091;
• App TV lint feat(catchup): normalize M3U archive timeline #288;
• Android TV focused device #458.

Compatibility note: the first implemented Xtream timeshift dialect derives the start value deterministically in UTC because the bounded source model does not persist provider/server archive timezone. Alternate panel timezone/dialect behavior is intentionally not claimed by this PR.