E5 S2: TMDB enrichment engine (Plex catalog)

Matches each mirrored Plex movie/show to TMDB by its stored canonical guid,
fetches once (append_to_response), and PERSISTS the enrichment onto the row —
served from the DB, never a live TMDB call at serve time. Additive: the
Plex-sourced imdb_rating/rating are untouched; tmdb_rating is the distinct
TMDb community score (ratings scope = TMDb + Plex's IMDb/audience, no OMDb/RT).

- config.py: tmdb_api_key + api_base/language/interval/batch defaults.
- sysconfig SPECS: tmdb_api_key (secret, Fernet) + tmdb_language, auto-rendered
  in the admin Config page; read like the Plex token.
- migration 0071 (ADD-only nullable, reversible): plex_items + plex_shows gain
  tmdb_id / tmdb_enriched_at (watermark) / tmdb_rating / tmdb_vote_count /
  budget / revenue / keywords / crew / studios / production_countries /
  recommendations / backdrops; plex_people gains tmdb_person_id (the S2
  foundation for S6 person bios). No watermark reset needed.
- app/plex/tmdb.py: TmdbClient (mirrors PlexClient; throttled; 404->None,
  transient->TmdbError), parse_tmdb / apply_tmdb_detail (one-parser rule),
  guid_to_tmdb_id (tmdb: direct, imdb:/tvdb: via /find), enrich_batch (movies
  then shows, transient error leaves the watermark NULL to retry, definitive
  no-match still stamps so it isn't re-fetched), _link_people (upserts
  tmdb_person_id by name), serve_block (recommendations resolved to library
  rows by guid), run_enrich (no-op without a key).
- scheduler: tmdb_enrich nightly job (default 120 min, no YouTube quota),
  runtime-tunable + "run now" from the Scheduler dashboard.
- detail endpoints emit `tmdb` (movies + shows) so it's curl-verifiable now;
  the FE render lands in S5.

Note: _link_people inserts plex_people rows for TMDB cast/crew; unreferenced
crew (composers etc., not in cast_names/directors) get pruned by the orphan
sweep — acceptable, the person page is cast-driven and cast rows survive.

Gate: ruff + py_compile green; backend test lane FULL suite 387 passed
(incl. migration drift downgrade->re-upgrade + test_plex_tmdb 9 tests).
Frontend unchanged since S1. Not merged (epic branch, stacks on S1).

backend/app/models.py

@@ -1067,6 +1067,20 @@ class PlexShow(Base, TimestampMixin, UpdatedAtMixin):
     imdb_id: Mapped[str | None] = mapped_column(String(16))  # tt… → the clickable IMDb link
     tagline: Mapped[str | None] = mapped_column(Text)
     full_cast: Mapped[list | None] = mapped_column(JSONB(none_as_null=True))  # ordered [{name, role, thumb}]
+    # --- TMDB enrichment (E5 S2): see the identical block on plex_items for the full rationale. Additive;
+    #     served from the row; NULL until enriched. (`budget`/`revenue` stay NULL for shows — TV has none.) ---
+    tmdb_id: Mapped[int | None] = mapped_column(Integer)
+    tmdb_enriched_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
+    tmdb_rating: Mapped[float | None] = mapped_column(Float)  # TMDb vote_average (0–10)
+    tmdb_vote_count: Mapped[int | None] = mapped_column(Integer)
+    budget: Mapped[int | None] = mapped_column(BigInteger)
+    revenue: Mapped[int | None] = mapped_column(BigInteger)
+    keywords: Mapped[list | None] = mapped_column(JSONB(none_as_null=True))  # [str]
+    crew: Mapped[list | None] = mapped_column(JSONB(none_as_null=True))  # [{name, job, tmdb_id, thumb}]
+    studios: Mapped[list | None] = mapped_column(JSONB(none_as_null=True))  # TMDB production companies [str]
+    production_countries: Mapped[list | None] = mapped_column(JSONB(none_as_null=True))  # [str]
+    recommendations: Mapped[list | None] = mapped_column(JSONB(none_as_null=True))
+    backdrops: Mapped[list | None] = mapped_column(JSONB(none_as_null=True))
     # Hungarian-metadata twin fields, written by the overlay sync (E5 S5). NULL = no HU twin matched,
     # so serving falls back to the EN columns. `people_text` is language-neutral, reused for both vectors.
     title_hu: Mapped[str | None] = mapped_column(String(512))
@@ -1184,6 +1198,24 @@ class PlexItem(Base, TimestampMixin, UpdatedAtMixin):
     imdb_id: Mapped[str | None] = mapped_column(String(16))  # tt… → the clickable IMDb link
     tagline: Mapped[str | None] = mapped_column(Text)
     full_cast: Mapped[list | None] = mapped_column(JSONB(none_as_null=True))  # ordered [{name, role, thumb}]
+    # --- TMDB enrichment (E5 S2): matched by the canonical `guid` ("tmdb:12345"), filled by the TMDB
+    #     backfill job, SERVED FROM THIS ROW (never a live TMDB call). Additive — imdb_rating/rating
+    #     above stay Plex-sourced; `tmdb_rating` is the distinct TMDb community score. NULL until enriched;
+    #     `tmdb_enriched_at` is the "tried" watermark (stamped on a definitive no-match too, so an
+    #     unresolvable title isn't re-fetched every run; left NULL only on a transient fetch error). ---
+    tmdb_id: Mapped[int | None] = mapped_column(Integer)
+    tmdb_enriched_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
+    tmdb_rating: Mapped[float | None] = mapped_column(Float)  # TMDb vote_average (0–10)
+    tmdb_vote_count: Mapped[int | None] = mapped_column(Integer)
+    budget: Mapped[int | None] = mapped_column(BigInteger)  # USD (movies; TV has none)
+    revenue: Mapped[int | None] = mapped_column(BigInteger)
+    keywords: Mapped[list | None] = mapped_column(JSONB(none_as_null=True))  # [str]
+    crew: Mapped[list | None] = mapped_column(JSONB(none_as_null=True))  # [{name, job, tmdb_id, thumb}]
+    studios: Mapped[list | None] = mapped_column(JSONB(none_as_null=True))  # TMDB production companies [str]
+    production_countries: Mapped[list | None] = mapped_column(JSONB(none_as_null=True))  # [str]
+    # [{tmdb_id, title, poster, media_type}] — resolved to library rows (by guid) at serve time.
+    recommendations: Mapped[list | None] = mapped_column(JSONB(none_as_null=True))
+    backdrops: Mapped[list | None] = mapped_column(JSONB(none_as_null=True))  # TMDB backdrop file_paths [str] (crossfade pool, S8)
     # Hungarian-metadata twin fields, written by the overlay sync (E5 S5). NULL = no HU twin matched
     # (serving falls back to the EN columns). `people_text` is language-neutral, reused for both vectors.
     title_hu: Mapped[str | None] = mapped_column(String(512))
@@ -1224,6 +1256,9 @@ class PlexPerson(Base, TimestampMixin, UpdatedAtMixin):
     id: Mapped[int] = mapped_column(primary_key=True)
     name: Mapped[str] = mapped_column(String(255), unique=True, index=True)
     photo_thumb: Mapped[str | None] = mapped_column(Text)  # proxied /person-image URL, or None
+    # TMDB person id, linked by name from a title's TMDB credits (E5 S2 lays the foundation; the /person
+    # biography fetch + person-page render land in S6). NULL until a TMDB-enriched title names this person.
+    tmdb_person_id: Mapped[int | None] = mapped_column(Integer)
 
 
 class PlexCollection(Base, TimestampMixin, UpdatedAtMixin):