feat(tmdb): add TmdbMovieInfo DTO and get_movie_info

Symmetric to TmdbShowInfo / get_tv_show_info — gives the upcoming
sync_movie orchestrator a typed cache snapshot for the v2 movie
library index.

* TmdbMovieInfo(tmdb_id, imdb_id, title, release_year)
* parse_movie_info(details, external_ids) — pure builder, parses
  release_year from the first 4 chars of release_date (None on
  missing/empty/non-numeric)
* TMDBClient.get_movie_info(tmdb_id) — aggregates
  /movie/{id} + /movie/{id}/external_ids and feeds the parser

Tests cover happy path, missing/null/empty imdb_id, every
release_year edge (none/empty/short/non-numeric/missing key),
and the two required-field errors (id, title).

tests/infrastructure/api/test_tmdb_client.py

@@ -360,6 +360,46 @@ class TestGetTvShowInfo:
         assert info.seasons == ()
 
 
+class TestGetMovieInfo:
+    """``get_movie_info`` aggregates ``/movie/{id}`` + external_ids."""
+
+    @patch("alfred.infrastructure.api.tmdb.client.requests.get")
+    def test_happy_path(self, mock_get, client):
+        details = {
+            "id": 27205,
+            "title": "Inception",
+            "release_date": "2010-07-16",
+        }
+        external = {"imdb_id": "tt1375666"}
+        mock_get.side_effect = [
+            _ok_response(details),
+            _ok_response(external),
+        ]
+
+        info = client.get_movie_info(27205)
+
+        assert info.tmdb_id == 27205
+        assert info.imdb_id == "tt1375666"
+        assert info.title == "Inception"
+        assert info.release_year == 2010
+
+    @patch("alfred.infrastructure.api.tmdb.client.requests.get")
+    def test_missing_imdb_id_becomes_none(self, mock_get, client):
+        mock_get.side_effect = [
+            _ok_response(
+                {
+                    "id": 1,
+                    "title": "X",
+                    "release_date": "2024-01-01",
+                }
+            ),
+            _ok_response({}),
+        ]
+        info = client.get_movie_info(1)
+        assert info.imdb_id is None
+        assert info.release_year == 2024
+
+
 class TestIsConfigured:
     def test_true_when_complete(self, client):
         assert client.is_configured() is True

tests/infrastructure/api/test_tmdb_dto.py

@@ -13,8 +13,10 @@ from datetime import date
 import pytest
 
 from alfred.infrastructure.api.tmdb.dto import (
+    TmdbMovieInfo,
     TmdbSeasonInfo,
     TmdbShowInfo,
+    parse_movie_info,
     parse_tv_show_info,
 )
 
@@ -166,3 +168,90 @@ class TestParseTvShowInfoErrors:
                 {},
                 today=REF_DATE,
             )
+
+
+# ════════════════════════════════════════════════════════════════════════════
+# parse_movie_info
+# ════════════════════════════════════════════════════════════════════════════
+
+
+def _movie_details(**overrides):
+    base = {
+        "id": 27205,
+        "title": "Inception",
+        "release_date": "2010-07-16",
+    }
+    base.update(overrides)
+    return base
+
+
+class TestParseMovieInfoHappyPath:
+    def test_minimal(self):
+        info = parse_movie_info(
+            _movie_details(),
+            {"imdb_id": "tt1375666"},
+        )
+        assert info == TmdbMovieInfo(
+            tmdb_id=27205,
+            imdb_id="tt1375666",
+            title="Inception",
+            release_year=2010,
+        )
+
+    def test_release_year_extracted_from_release_date(self):
+        info = parse_movie_info(
+            _movie_details(release_date="1999-03-31"),
+            {},
+        )
+        assert info.release_year == 1999
+
+
+class TestParseMovieInfoImdb:
+    def test_missing_imdb_id_becomes_none(self):
+        info = parse_movie_info(_movie_details(), {})
+        assert info.imdb_id is None
+
+    def test_null_imdb_id_becomes_none(self):
+        info = parse_movie_info(_movie_details(), {"imdb_id": None})
+        assert info.imdb_id is None
+
+    def test_empty_string_imdb_id_becomes_none(self):
+        info = parse_movie_info(_movie_details(), {"imdb_id": ""})
+        assert info.imdb_id is None
+
+
+class TestParseMovieInfoReleaseYear:
+    def test_no_release_date_yields_none(self):
+        info = parse_movie_info(_movie_details(release_date=None), {})
+        assert info.release_year is None
+
+    def test_empty_release_date_yields_none(self):
+        info = parse_movie_info(_movie_details(release_date=""), {})
+        assert info.release_year is None
+
+    def test_release_date_too_short_yields_none(self):
+        info = parse_movie_info(_movie_details(release_date="201"), {})
+        assert info.release_year is None
+
+    def test_release_date_non_numeric_prefix_yields_none(self):
+        info = parse_movie_info(_movie_details(release_date="soon"), {})
+        assert info.release_year is None
+
+    def test_missing_release_date_yields_none(self):
+        # release_date key absent from the payload.
+        info = parse_movie_info({"id": 1, "title": "X"}, {})
+        assert info.release_year is None
+
+
+class TestParseMovieInfoErrors:
+    def test_missing_id_raises(self):
+        with pytest.raises(ValueError, match="'id'"):
+            parse_movie_info({"title": "X"}, {})
+
+    def test_missing_title_raises(self):
+        with pytest.raises(ValueError, match="'title'"):
+            parse_movie_info({"id": 1}, {})
+
+    def test_empty_title_raises(self):
+        with pytest.raises(ValueError, match="'title'"):
+            parse_movie_info({"id": 1, "title": ""}, {})