feat(picker): add series and studio rows from IGDB credits

New V37 tables game_credit and game_credit_check store IGDB
collections and developer/publisher companies per game.
A scheduled job backfills existing games (250 per 30 s);
sync, import, manual add, merge and detail page refresh them.
SERIES row: next part of a collection the user played.
STUDIO row: backlog games from developers of top played games.

src/main/resources/application.yml

@@ -64,6 +64,10 @@ app:
     achievement-ttl-hours: 1
     schema-ttl-days: 30
     speedrun-ttl-days: 30
+    # Existing games get their IGDB series and companies in batches; 2 IGDB requests per batch.
+    credit-ttl-days: 30
+    credit-backfill-ms: 30000
+    credit-backfill-batch: 250
     edition-ttl-days: 30
     release-ttl-days: 30
     # Reported broken pictures, repaired after the nightly sync.