- Create migration 2026-02-03_add_auth_locked_index.sql
- Add partial index on locked_until with active lockout condition
- Replace previous generic locked_until index with optimized version
- Index filters for locked_until IS NOT NULL AND locked_until > NOW()
- Improves query performance for account unlock validation
- Resolves GAP-009
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>