feat(discovery): DiscoverySuggestion schema + WatchedArtist.lastDiscoveredAt

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

worker/tests/test_discovery_schema.py

@@ -0,0 +1,31 @@
+import psycopg
+import pytest
+
+from tests.conftest import insert_discovery_suggestion, insert_watched_artist
+
+
+def test_suggestion_round_trip(conn):
+    sid = insert_discovery_suggestion(
+        conn, kind="album", artist_mbid="a1", artist_name="Boygenius",
+        rg_mbid="rg1", album="the record", score=2.5, seed_count=2,
+        sources=["listenbrainz"], status="pending",
+    )
+    with conn.cursor() as cur:
+        cur.execute(
+            'SELECT kind::text, "artistName", "rgMbid", album, score, "seedCount", '
+            'sources, status::text FROM "DiscoverySuggestion" WHERE id = %s', (sid,))
+        assert cur.fetchone() == (
+            "album", "Boygenius", "rg1", "the record", 2.5, 2, ["listenbrainz"], "pending")
+
+
+def test_dedupe_key_is_unique(conn):
+    insert_discovery_suggestion(conn, kind="artist", artist_mbid="dup", rg_mbid=None)
+    with pytest.raises(psycopg.errors.UniqueViolation):
+        insert_discovery_suggestion(conn, kind="artist", artist_mbid="dup", rg_mbid=None)
+
+
+def test_watched_artist_has_last_discovered_column(conn):
+    insert_watched_artist(conn, mbid="a1", last_discovered_sql="now()")
+    with conn.cursor() as cur:
+        cur.execute('SELECT "lastDiscoveredAt" IS NOT NULL FROM "WatchedArtist" WHERE mbid = %s', ("a1",))
+        assert cur.fetchone()[0] is True