refactor(tmdb): ACL pass — push VOs into DTOs, split search per media type

Anti-corruption boundary tightened on the TMDB adapter:

* TmdbMovieInfo / TmdbShowInfo now carry domain VOs (TmdbId, ImdbId,
  MovieTitle, ReleaseYear, ShowStatus) instead of raw scalars —
  validation happens at the boundary, not three layers later.
* ShowStatus enum added (domain/tv_shows/value_objects) with a
  from_tmdb() mapper that falls back to UNKNOWN + logs a warning on
  unrecognized values. TVShow.status is now ShowStatus, not str.
* MovieTitle cap raised from 100 to 150 chars.
* MediaResult / ExternalIds dropped. Replaced by per-media search
  DTOs: TmdbMovieSearchResult and TmdbShowSearchResult. Neither
  carries imdb_id — search no longer enriches with external_ids
  (callers needing imdb_id follow up with get_movie_info /
  get_tv_show_info on the chosen tmdb_id).
* TMDBClient: search_multi / search_media / _parse_result removed.
  search_movies (/search/movie) and search_shows (/search/tv) added,
  each parsing hits into VO-typed DTOs.
* SearchMovieUseCase returns a list of MovieHit (flattened to
  primitives for the agent). New symmetric SearchShowUseCase +
  ShowHit / SearchShowResponse DTOs.
* agent/tools/api.py: find_media_imdb_id → search_movies +
  search_shows wrappers.
* FileEntry moved from domain/shared/ports/filesystem_scanner.py to
  domain/shared/file_entry.py (it's a DTO, not a Protocol); size_kb
  (float) → size (int bytes). Scanner and SubtitleIdentifier
  updated.

Tests: 79/79 pass on tests/infrastructure/api/ +
tests/application/test_search_movie.py +
tests/application/test_search_show.py.

tests/infrastructure/persistence/dot_alfred/v2/conftest.py

@@ -24,7 +24,7 @@ from alfred.domain.releases.entities import (
 from alfred.domain.releases.value_objects import EpisodeRange, ReleaseMode
 from alfred.domain.shared.media import AudioTrack, SubtitleTrack
 from alfred.domain.shared.value_objects import FilePath, ImdbId, TmdbId
-from alfred.domain.tv_shows.value_objects import EpisodeNumber, SeasonNumber
+from alfred.domain.tv_shows.value_objects import EpisodeNumber, SeasonNumber, ShowStatus
 from alfred.infrastructure.api.tmdb.dto import TmdbSeasonInfo, TmdbShowInfo
 
 
@@ -164,10 +164,10 @@ def inception_release() -> MovieRelease:
 def foundation_tmdb_info() -> TmdbShowInfo:
     """Foundation TMDB cache snapshot — 3 seasons, S03 not yet aired."""
     return TmdbShowInfo(
-        tmdb_id=84958,
-        imdb_id="tt0804484",
+        tmdb_id=TmdbId(84958),
+        imdb_id=ImdbId("tt0804484"),
         name="Foundation",
-        status="Returning Series",
+        status=ShowStatus.RETURNING_SERIES,
         seasons=(
             TmdbSeasonInfo(number=1, episode_count=10, aired=True),
             TmdbSeasonInfo(number=2, episode_count=10, aired=True),