fix(plex): the recs rail's anchor and a held recommendation are named in the reader's language (E30 S1b)

Found in the S1b UAT: 'Mert megnézted: Batman Forever' kept the English title, and
the info page's TMDB recommendations kept TMDB's English titles even for titles we
hold. A held recommendation is now named as the library names it, in the reader's
language; one we lack keeps TMDB's title.

backend/app/plex/tmdb.py

@@ -21,6 +21,7 @@ from sqlalchemy.orm import Session
 from app import logs, sysconfig
 from app.config import settings
 from app.models import PlexItem, PlexPerson, PlexShow
+from app.plex.cards import display_title
 
 log = logs.get_logger(__name__)
 # Politeness throttle: TMDB tolerates ~50 req/s; ~33/s leaves comfortable headroom for a shared host.
@@ -406,10 +407,11 @@ def resolve_library_guids(
     return movies, shows
 
 
-def resolve_recs(db: Session, recs: list[dict] | None) -> list[dict]:
+def resolve_recs(db: Session, recs: list[dict] | None, *, lang: str) -> list[dict]:
     """Tag each recommendation with whether it's in OUR library (matched by guid `tmdb:<id>`, bucketed
     by media_type — see resolve_library_guids) and, if so, its rating_key — so the client can deep-link
-    the ones we have and merely display the rest."""
+    the ones we have and merely display the rest. One we have is named as the library names it, in
+    `lang` (E30); one we lack keeps the title TMDB gave."""
     if not recs:
         return []
     movies, shows = resolve_library_guids(db, recs)
@@ -417,13 +419,19 @@ def resolve_recs(db: Session, recs: list[dict] | None) -> list[dict]:
     for r in recs:
         g = f"tmdb:{r.get('tmdb_id')}"
         row = shows.get(g) if r.get("media_type") == "tv" else movies.get(g)
+        named = {"title": display_title(row, lang)} if row is not None else {}
         out.append(
-            {**r, "in_library": row is not None, "rating_key": row.rating_key if row else None}
+            {
+                **r,
+                **named,
+                "in_library": row is not None,
+                "rating_key": row.rating_key if row else None,
+            }
         )
     return out
 
 
-def serve_block(db: Session, row) -> dict | None:
+def serve_block(db: Session, row, *, lang: str) -> dict | None:
     """The TMDB extras for a movie/show detail response, served from the row (no live TMDB call).
     None until the row has been TMDB-enriched (the client then shows nothing extra)."""
     if row.tmdb_enriched_at is None:
@@ -438,7 +446,7 @@ def serve_block(db: Session, row) -> dict | None:
         "crew": row.crew or [],
         "studios": row.studios or [],
         "production_countries": row.production_countries or [],
-        "recommendations": resolve_recs(db, row.recommendations),
+        "recommendations": resolve_recs(db, row.recommendations, lang=lang),
         "backdrops": row.backdrops or [],
     }