- Resolve database URL once per request in admin.py
- Include CONFIG.database.params in get_database_url() for SSL support
- Rename _db_cred_provider to db_cred_provider (public API)
- Add tests for get_database_url() with special characters
- Extract shared self_signed_cert fixture for SSL tests

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>