PostgreSQL migration: Complete code preparation phase
- Add db_helpers.py with cross-database upsert functions for SQLite/PostgreSQL
- Replace 12 on_conflict_replace() calls with PostgreSQL-compatible upserts
- Add unique indexes: StratPlay(game, play_num), Decision(game, pitcher)
- Add max_length to Team model fields (abbrev, sname, lname)
- Fix boolean comparison in teams.py (== 0/1 to == False/True)
- Create migrate_to_postgres.py with ID-preserving migration logic
- Create audit_sqlite.py for pre-migration data integrity checks
- Add PROJECT_PLAN.json for migration tracking
- Add .secrets/ to .gitignore for credentials
Audit results: 658,963 records across 29 tables, 2,390 orphaned stats (expected)
Based on Major Domo migration lessons learned (33 issues resolved there)
0cba52cea5