Each batch job now writes its results to a Postgres table in addition to
the existing Parquet/CSV output. OpeningBookJob → analytics_opening_stats,
PlayerStatsJob → analytics_player_stats, PlayerClusteringJob →
analytics_player_clusters + analytics_cluster_archetypes, PlayerGraphJob
→ analytics_player_graph. MLlib Vector columns are excluded from the JDBC
write by reusing the already-selected scalar DataFrame in
PlayerClusteringJob.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>