Replace non-blocking git-secrets with mandatory gitleaks scanning:
- Pre-commit: blocks commit if gitleaks not installed or secrets found
- CI: pinned gitleaks Docker image scans each commit in Woodpecker
- Shared .gitleaks.toml with 12 custom rules for database URLs,
alembic.ini, bearer tokens, PEM keys, docker-compose secrets, etc.
- Stopwords suppress localhost/changeme/placeholder false positives
- Install/verify scripts updated for gitleaks (no longer optional)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
