Persist Item.source_url so the details-page Source chip survives fallback

- stored_metadata_fallback() had no source_url, so
  _build_detail_link_sections() silently dropped the whole Source
  section whenever the details page fell back to stored Item metadata
  (e.g. a live provider fetch fails).
- IGDB, Hardcover, ComicVine, and MangaUpdates embed a provider-generated
  slug in source_url that can't be rebuilt from media_id alone, so persist
  it on Item (synced via apply_item_metadata on every live fetch) instead
  of a per-source URL-rebuilding helper.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: dannyvfilms

src/app/metadata_utils.py

@@ -10,6 +10,7 @@
 
 CORE_METADATA_FIELDS = [
     "synopsis",
+    "source_url",
     "country",
     "languages",
     "platforms",
@@ -147,6 +148,7 @@ def extract_item_metadata_values(metadata: dict | None) -> dict[str, object]:
 
     return {
         "synopsis": payload.get("synopsis") or "",
+        "source_url": payload.get("source_url") or "",
         "country": details.get("country") or "",
         "languages": _coerce_list(details.get("languages")),
         "platforms": _coerce_list(details.get("platforms"), allow_scalar=False),

src/app/migrations/0166_item_source_url.py

@@ -0,0 +1,48 @@
+from django.db import migrations, models
+
+
+def _column_exists(schema_editor, table_name, column_name):
+    """Return True when a database column already exists."""
+    connection = schema_editor.connection
+    if connection.vendor == "postgresql":
+        with connection.cursor() as cursor:
+            cursor.execute(
+                "SELECT 1 FROM information_schema.columns "
+                "WHERE table_schema = current_schema() "
+                "AND table_name = %s AND column_name = %s",
+                [table_name, column_name],
+            )
+            return cursor.fetchone() is not None
+    with connection.cursor() as cursor:
+        description = connection.introspection.get_table_description(cursor, table_name)
+        columns = {getattr(column, "name", column[0]) for column in description}
+        return column_name in columns
+
+
+class AddFieldIfNotExists(migrations.AddField):
+    """Add a field only when the backing column doesn't already exist."""
+
+    def database_forwards(self, app_label, schema_editor, from_state, to_state):
+        to_model = to_state.apps.get_model(app_label, self.model_name)
+        field = to_model._meta.get_field(self.name)
+        if _column_exists(schema_editor, to_model._meta.db_table, field.column):
+            return
+        super().database_forwards(app_label, schema_editor, from_state, to_state)
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("app", "0164_musicreleasepreference"),
+    ]
+
+    operations = [
+        AddFieldIfNotExists(
+            model_name="item",
+            name="source_url",
+            field=models.TextField(
+                blank=True,
+                default="",
+                help_text="Cached provider detail page URL, used as a fallback when live metadata is unavailable",
+            ),
+        ),
+    ]

src/app/models/item.py

@@ -47,6 +47,11 @@ class Item(CalendarTriggerMixin, models.Model):
         default="",
         help_text="Cached provider synopsis, used as a fallback when live metadata is unavailable",
     )
+    source_url = models.TextField(
+        blank=True,
+        default="",
+        help_text="Cached provider detail page URL, used as a fallback when live metadata is unavailable",
+    )
     image = models.TextField(
         blank=True, default=""
     )  # if add default, custom media entry will show the value

src/app/services/metadata_fallback.py

@@ -12,6 +12,7 @@ def stored_metadata_fallback(item):
         "localized_title": item.localized_title,
         "image": item.image,
         "synopsis": item.synopsis,
+        "source_url": item.source_url,
         "genres": item.genres,
         "cast": [],
         "crew": [],

src/app/tests/views/test_media_details.py

@@ -493,7 +493,60 @@ def test_media_details_keeps_tracked_tmdb_show_available_when_provider_returns_4
         self.assertEqual(response.context["current_instance"], tv)
 
     @patch("app.providers.services.get_media_metadata")
-    def test_media_details_renders_top_action_row_between_chips_and_description(
+    def test_media_details_keeps_source_link_when_provider_is_unreachable(
+        self,
+        mock_get_metadata,
+    ):
+        """The "Source" chip survives falling back to stored Item metadata (#931-style)."""
+        service_unavailable_response = requests.Response()
+        service_unavailable_response.status_code = requests.codes.service_unavailable
+        mock_get_metadata.side_effect = services.ProviderAPIError(
+            Sources.IGDB.value,
+            requests.exceptions.HTTPError(response=service_unavailable_response),
+        )
+
+        item = Item.objects.create(
+            media_id="1473",
+            source=Sources.IGDB.value,
+            media_type=MediaTypes.GAME.value,
+            title="Zone of the Enders: The 2nd Runner",
+            image="https://example.com/zoe.jpg",
+            synopsis="Stored synopsis",
+            source_url="https://www.igdb.com/games/zone-of-the-enders-the-2nd-runner",
+        )
+        Game.objects.create(
+            item=item,
+            user=self.user,
+            status=Status.IN_PROGRESS.value,
+        )
+
+        response = self.client.get(
+            reverse(
+                "media_details",
+                kwargs={
+                    "source": Sources.IGDB.value,
+                    "media_type": MediaTypes.GAME.value,
+                    "media_id": item.media_id,
+                    "title": "zone-of-the-enders-the-2nd-runner",
+                },
+            ),
+            {"fragment": "secondary"},
+        )
+
+        self.assertEqual(response.status_code, 200)
+        source_sections = [
+            section
+            for section in response.context["detail_link_sections"]
+            if section["title"] in ("Source", "Tracking Source")
+        ]
+        self.assertTrue(source_sections, "Expected a Source link section in the fallback")
+        self.assertEqual(
+            source_sections[0]["entries"][0]["url"],
+            "https://www.igdb.com/games/zone-of-the-enders-the-2nd-runner",
+        )
+
+    @patch("app.providers.services.get_media_metadata")
+    def test_media_details_renders_action_row_before_chips_and_description(
         self, mock_get_metadata
     ):
         mock_get_metadata.return_value = {
@@ -567,8 +620,10 @@ def test_media_details_renders_top_action_row_between_chips_and_description(
             'class="hidden text-[var(--color-link)] hover:text-[var(--color-link-hover)] text-sm mt-2 focus:outline-none transition-colors cursor-pointer sm:inline-flex"',
             content,
         )
-        self.assertLess(content.index("tmdb-logo.png"), content.index("Add to tracker"))
-        self.assertLess(content.index("Add to tracker"), content.index("Test overview"))
+        # Movies/TV/seasons render the carousel-column layout: title + action row
+        # come first, score chips move below them, then the synopsis.
+        self.assertLess(content.index("Add to tracker"), content.index("tmdb-logo.png"))
+        self.assertLess(content.index("tmdb-logo.png"), content.index("Test overview"))
 
     @patch("app.providers.services.get_media_metadata")
     def test_comic_volume_issue_rows_render_shared_action_buttons(