<!-- directive-density: intentional (teaches migration anti-patterns; NEVER markers describe real production-break conditions, not aspirational guidance) -- Database Patterns Comprehensive patterns for database migrations, schema design, and version management. Each category has individual rule files in loaded on-demand. Quick Reference | Category | Rules | Impact | When to Use | |----------|-------|--------|-------------| | Alembic Migrations | 3 | CRITICAL | Autogenerate, data migrations, branch management | | Schema Design | 3 | HIGH | Normalization, indexing strategies, NoSQL patterns | |…