fix(db): PostgreSQL P0 fixes - SQL_KEYWORDS expansion, timeout config, and tests
- Expand SQL_KEYWORDS from ~120 to 226+ words covering:
- Window functions (ROW_NUMBER, RANK, LAG, LEAD, etc.)
- CTEs (WITH, RECURSIVE, MATERIALIZED, etc.)
- Advanced grouping (ROLLUP, CUBE, GROUPING SETS)
- JSON operations, types, table sampling
- Transaction control and other PostgreSQL-specific keywords
- Add connection pool timeout configuration:
- connectionTimeoutMillis: 10s
- statement_timeout: 30s (PostgreSQL level)
- idleTimeoutMillis: 30s (connection cleanup)
- query_timeout: 60s (driver-level fallback)
- Add 12 comprehensive edge case tests covering:
- Window functions, CTEs, advanced grouping
- CASE expressions, set operations, JSON operators
- All 38 tests pass
Production-ready: prevents hung queries and supports complex SQL.
7601b5f176