## What changed
- Add a best-effort `network/policyDecision` notification for final domain and non-domain policy decisions made by executor-local proxies.
- Validate notifications against the active process on the controller and emit audit events with controller-trusted session and execution metadata.
- Reserve outbound RPC capacity so audit notifications cannot block control messages, and expose valid `chatgpt-account-id` header values for audit attribution.
## Testing
- Cover notification serialization, proxy decision capture, executor-to-controller delivery, trusted metadata handling, and reserved RPC capacity.
GitOrigin-RevId: a39f96a6b3d9401c03d54eaef5b9a6d3fe0da78b