fix: 清理音乐刮削结果中 album_type 等字段的尾部空格 (#6327)

MusicBrainz 和 ListenBrainz 模块从 API 响应中提取 album_type、
secondary_types 时直接使用 dict.get() 取值，未做 strip() 处理，
导致部分结果带有尾部空格（如 'Album '、'Broadcast '）。

修复：
- MusicBrainz 新增 _stripped() 工具方法，3 处 album_type 赋值统一清理
- ListenBrainz 新增 _stripped() 工具方法，_fresh_release_to_info 中清理
- Pydantic schema 层增加 field_validator 作为兜底安全网
- 新增 9 个回归测试覆盖所有场景

tests/test_music_album_type_strip.py

@@ -0,0 +1,150 @@
+"""音乐刮削结果中 album_type 等字段不应包含两端空白（Issue #6327）。"""
+
+from app.modules.listenbrainz import ListenBrainzModule
+from app.modules.musicbrainz import MusicBrainzModule
+from app.schemas.music import MusicAlbumInfo as SchemaMusicAlbumInfo
+from app.schemas.music import MusicInfo as SchemaMusicInfo
+
+
+class TestMusicBrainzAlbumTypeStripped:
+    """MusicBrainz 模块应将 album_type 和 secondary_types 两端空白去除。"""
+
+    def test_release_to_album_album_type_stripped(self):
+        """专辑详情中 primary-type 带尾部空格时应被清理。"""
+        detail = {
+            "id": "release-1",
+            "title": "Test Album",
+            "artist-credit": [{"name": "Artist", "artist": {"id": "a1"}}],
+            "release-group": {
+                "id": "rg-1",
+                "primary-type": "Album ",
+                "secondary-types": ["Compilation ", " Soundtrack"],
+            },
+            "date": "2024-01-01",
+            "media": [],
+        }
+
+        album = MusicBrainzModule._release_to_album(detail)
+
+        assert album is not None
+        assert album.album_type == "Album"
+        assert album.secondary_types == ["Compilation", "Soundtrack"]
+
+    def test_recording_to_info_album_type_stripped(self):
+        """歌曲识别结果中 album_type 和 category 不应包含空白。"""
+        recording = {
+            "id": "rec-1",
+            "title": "Test Song",
+            "artist-credit": [{"name": "Artist", "artist": {"id": "a1"}}],
+            "length": 300000,
+            "isrcs": ["USRC10000001"],
+            "genres": [],
+            "releases": [
+                {
+                    "id": "rel-1",
+                    "title": "Test Single",
+                    "artist-credit": [{"name": "Artist", "artist": {"id": "a1"}}],
+                    "release-group": {
+                        "id": "rg-1",
+                        "primary-type": "Single ",
+                        "secondary-types": [" Remix "],
+                    },
+                },
+            ],
+        }
+
+        info = MusicBrainzModule._recording_to_info(recording)
+
+        assert info is not None
+        assert info.album_type == "Single"
+        assert info.category == "Single / Remix"
+
+    def test_release_group_to_album_strips_types(self):
+        """Release Group 浏览结果中 album_type 和 secondary_types 应被清理。"""
+        release_group = {
+            "id": "rg-1",
+            "title": "Test EP",
+            "artist-credit": [{"name": "Artist", "artist": {"id": "a1"}}],
+            "primary-type": "EP ",
+            "secondary-types": ["Live ", " Compilation "],
+            "first-release-date": "2024",
+            "rating": {"value": "4", "votes-count": "10"},
+        }
+
+        album = MusicBrainzModule._release_group_to_album(release_group)
+
+        assert album is not None
+        assert album.album_type == "EP"
+        assert album.secondary_types == ["Live", "Compilation"]
+
+
+class TestListenBrainzAlbumTypeStripped:
+    """ListenBrainz 模块应将 album_type 和 category 两端空白去除。"""
+
+    def test_fresh_release_to_info_strips_album_type(self):
+        """新发行条目中 release_group_primary_type 带空格时应被清理。"""
+        release = {
+            "release_group_mbid": "rg-1",
+            "release_name": "Test Album",
+            "artist_credit_name": "Artist",
+            "release_group_primary_type": "Album ",
+            "release_group_secondary_type": " Compilation ",
+            "release_date": "2024-01-01",
+        }
+
+        info = ListenBrainzModule._fresh_release_to_info(release)
+
+        assert info is not None
+        assert info.album_type == "Album"
+        assert info.category == "Album / Compilation"
+
+    def test_fresh_release_to_info_handles_none_type(self):
+        """空白的 release_group_primary_type 应返回 None。"""
+        release = {
+            "release_group_mbid": "rg-1",
+            "release_name": "Test Album",
+            "artist_credit_name": "Artist",
+            "release_group_primary_type": "  ",
+            "release_date": "2024-01-01",
+        }
+
+        info = ListenBrainzModule._fresh_release_to_info(release)
+
+        assert info is not None
+        assert info.album_type is None
+
+
+class TestSchemaAlbumTypeValidator:
+    """Pydantic schema 应作为兜底清理 album_type 两端空白。"""
+
+    def test_music_info_schema_strips_album_type(self):
+        """MusicInfo schema 构造时 album_type 尾部空格应被去除。"""
+        info = SchemaMusicInfo(
+            album_type="Broadcast ",
+            title="Test",
+        )
+        assert info.album_type == "Broadcast"
+
+    def test_music_album_info_schema_strips_album_type(self):
+        """MusicAlbumInfo schema 构造时 album_type 尾部空格应被去除。"""
+        album = SchemaMusicAlbumInfo(
+            album_type="EP ",
+            title="Test EP",
+        )
+        assert album.album_type == "EP"
+
+    def test_schema_blank_album_type_becomes_none(self):
+        """纯空白的 album_type 应被归一为 None。"""
+        info = SchemaMusicInfo(
+            album_type="  ",
+            title="Test",
+        )
+        assert info.album_type is None
+
+    def test_schema_none_album_type_stays_none(self):
+        """None 值的 album_type 应保持不变。"""
+        info = SchemaMusicInfo(
+            album_type=None,
+            title="Test",
+        )
+        assert info.album_type is None