Per-node onboarding tokens replace the placeholder <token> in the agent
connect command: raw cagt_ tokens are returned once at issuance, only
sha256 hashes persist in agent_auth_tokens, and listing exposes metadata
only. Public agent routes accept env-configured shared tokens or any
active DB-issued token; successful validation stamps last_used_at and
revoked tokens are rejected — verified end-to-end against a real stack
(register, heartbeat, revoke → 401, bogus → 401).
Generated with [Devin](https://devin.ai)
Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>
