Use xata_id for scrobble deduplication in feed

apps/api/src/xrpc/app/rocksky/feed/getNowPlayings.ts

···
         .leftJoin(tracks, eq(scrobbles.trackId, tracks.id))
         .leftJoin(users, eq(scrobbles.userId, users.id))
         .where(
-          sql`scrobbles.id IN (
-            SELECT DISTINCT ON (inner_s.user_id) inner_s.id
+          sql`scrobbles.xata_id IN (
+            SELECT DISTINCT ON (inner_s.user_id) inner_s.xata_id
             FROM scrobbles inner_s
-            ORDER BY inner_s.user_id, inner_s.timestamp DESC, inner_s.id DESC
+            ORDER BY inner_s.user_id, inner_s.timestamp DESC, inner_s.xata_id DESC
           )`,
         )
         .orderBy(desc(scrobbles.timestamp))