Phase 4: dynamic extras fetched LIVE per view (providers change, so not cached)
via GET /detail/<kind>/<id>/extras → engine.item_extras → TMDB
(videos + watch/providers + similar in one call).
- Trailer: a '▶ Trailer' action that opens an in-app YouTube modal embed (Esc /
click-away to close).
- Where to Watch: provider logos for the region (JustWatch via TMDB).
- More Like This: a poster row of similar titles linking out to TMDB.
Both movie + show pages; all keyless (same TMDB key).
Seam tests: extras parse (trailer priority, provider/similar shape), item_extras
gating on tmdb_id, route registered, markup hooks. (RT/Metacritic via OMDb needs
its own key — offered separately.)