#23 Issue 23: [Security] Admin "Clawback" Grace Period

[JerryIdoko]

Description:
If an Admin accidentally creates a vault with 1,000,000 tokens instead of 100,000, they need a short window to undo it before the beneficiary claims it.
Acceptance Criteria:

[ ] Add a hardcoded 1-hour grace_period starting from vault_creation_time.

[ ] Implement clawback_vault(vault_id) that allows the Admin to cancel and retrieve 100% of the funds, but only if current_time < creation_time + 1_hour.
Labels: security, safety