## What changed
- Add client-side handling for exec-server network policy requests, including request validation, per-process decision routing, and allow, deny, or ask responses.
- Bound concurrent callbacks and fail closed when requests are invalid, exceed capacity, time out, or outlive their process session.
- Replace the callback opt-in flag with a launch-level `policyDecisionTimeoutMs` value and include transport overhead in the executor timeout.
- Preserve callback admission limits across connection recovery and clean up policy state when process startup is abandoned or a session ends.
## Testing
- Cover decision forwarding, invalid and excess requests, cancellation during process cleanup, abandoned starts, timeout propagation, and launch-config serialization.
GitOrigin-RevId: 6ee2a0139e0f8170cf1a5cdd646bd811b7d3c1f6