Discogs (#848 follow-up): tag collection album IDs for consistency

The Your Albums Discogs collection sync stored bare release_ids while
search/discography now store tagged ('r<id>') ones (#848). This didn't cause a live
bug — the pool dedups by normalized name, and discogs_release_id is only ever
re-fetched (which handles bare via release-first) — but it left the "type travels
with the ID" invariant half-applied. Now the collection sync tags its IDs too, so
every stored Discogs album ID is uniform and a future ID comparison can't be tripped
by mixed forms.

Collection items are always releases, so they're tagged 'r<id>'. Test locks the
stored value + that a tagged collection ID routes only to /releases (never /masters).

tests/test_discogs_collection_id_tagging.py

@@ -0,0 +1,40 @@
+"""#848 follow-up: the Your Albums Discogs collection sync stores album IDs
+TAGGED ('r<id>') like search/discography, so every stored Discogs album ID is
+uniform and re-fetches route to the correct endpoint (no master/release collision).
+
+The divergence didn't cause a live bug (the pool dedups by normalized name, and
+discogs_release_id is only ever re-fetched — which handles bare too); this locks
+in the consistency so a future ID comparison can't be tripped by mixed forms.
+"""
+
+from __future__ import annotations
+
+import pytest
+
+from core.discogs_client import _tag_discogs_album_id, _discogs_album_endpoints
+from database.music_database import MusicDatabase
+
+
+def test_collection_release_id_is_tagged_and_routes_to_releases_only(tmp_path):
+    db = MusicDatabase(str(tmp_path / "m.db"))
+    # Exactly what the Your Albums Discogs sync now passes (collection = releases).
+    ok = db.upsert_liked_album(
+        album_name="Some Album", artist_name="Some Artist",
+        source_service="discogs",
+        source_id=_tag_discogs_album_id(7361634, "release"), source_id_type="discogs",
+        profile_id=1,
+    )
+    assert ok
+    with db._get_connection() as conn:
+        row = conn.execute(
+            "SELECT discogs_release_id FROM liked_albums_pool WHERE profile_id = 1"
+        ).fetchone()
+    assert row is not None
+    assert row["discogs_release_id"] == "r7361634"            # stored tagged, not bare
+    # A tagged collection ID routes ONLY to /releases — never /masters — so it
+    # can't hit the master/release collision #848 fixed.
+    assert _discogs_album_endpoints("r7361634") == ["/releases/7361634"]
+
+
+def test_tagged_collection_id_never_hits_masters():
+    assert "/masters/" not in " ".join(_discogs_album_endpoints(_tag_discogs_album_id(123, "release")))

web_server.py

@@ -29638,11 +29638,15 @@ def _fetch_liked_albums(profile_id: int):
             if discogs_cl.is_authenticated():
                 logger.info("[Your Albums] Fetching collection from Discogs...")
                 releases = discogs_cl.get_user_collection()
+                from core.discogs_client import _tag_discogs_album_id
                 for r in releases:
                     database.upsert_liked_album(
                         album_name=r['album_name'], artist_name=r['artist_name'],
                         source_service='discogs',
-                        source_id=str(r['release_id']), source_id_type='discogs',
+                        # Collection items are always releases — store the ID tagged
+                        # ('r<id>') to match search/discography (#848), so every stored
+                        # Discogs album ID is uniform and re-fetches route correctly.
+                        source_id=_tag_discogs_album_id(r['release_id'], 'release'), source_id_type='discogs',
                         image_url=r.get('image_url'), release_date=r.get('release_date', ''),
                         total_tracks=r.get('total_tracks', 0), profile_id=profile_id
                     )