Adds a test script that validates the entire A2H2A approval process, from ticket creation to final verification in Firestore.
- The server now supports a `test_mode` flag to facilitate testing.
- The test verifies ticket creation, review page access, approval, final ticket status, and audit log creation.
Implements a secure, state-only approval workflow for A2H2A tickets.
- Adds single-use token generation and validation.
- Implements an IAP-gated HTML review page.
- Adds state-changing approve/reject endpoints with full validation.
- Introduces audit logging for ticket events.
- Execution of tools remains disabled.
