Implement approval-policy evaluation and human-gate workflow

[labgadget015-dotcom]

Roadmap item 4/10 · Workstream: Security · Risk: High · Approval required: Yes · Target milestone: M2 — Governed intake

Objective

Evaluate every proposed agent action against config/policies.yaml and the risk score, and route anything that needs approval to a human gate that costs the approver one step (per docs/human-in-the-loop-protocol.md), with the decision recorded as an audit event.

Non-goals

• A general RBAC system
• Approvals for actions outside this platform
• Auto-approving new action classes

Acceptance criteria

• Single evaluation entry point returns allow / require_approval / deny with the matched rule and risk band (core/policy_engine.py, core/risk_scorer.py)
• Unknown or unmapped actions default to require_approval (fail closed), never allow
• Protected paths (.github/workflows/, config/, core/) always require approval
• Human gate: pending approval surfaced as one actionable item (GitHub comment/label or Slack) with approve/deny; timeout = deny
• Approval decisions emitted as audit events with approver, decision, correlation ID (Implement correlation IDs, idempotency, and structured audit events #319)
• Dry-run remains the default; approval never bypasses dry-run

Dependencies

• Define canonical domain schemas and event envelope #318
• Implement correlation IDs, idempotency, and structured audit events #319

Risk

High — a policy bug either blocks all automation or silently allows destructive actions.

Test evidence required

• Table-driven tests for every rule in config/policies.yaml plus unknown-action and protected-path cases
• Test that timeout and malformed approval responses resolve to deny
• Recorded dry-run of one gated action through approve and deny paths

Definition of done

• Merged with tests; policy decision audit events visible
• Protocol doc updated with the concrete one-step handoff
• No existing auto-approved action changes behaviour without an explicit changelog entry
• Evidence URL and Correlation ID recorded on the project item