## What changed
- Start inbound exec-server request spans when messages enter the connection queue and carry them through dispatch and response handling.
- Record request outcomes for client-handled network policy callbacks, including errors and disconnections.
- Add the `exec_server_request_queue_duration_seconds` histogram, labeled by bounded route name, while excluding synchronous route setup time.
## Testing
- Cover span lifetime and trace-parent propagation across server and client queues.
- Verify queue-duration telemetry and outcome recording for completed, rejected, and cancelled requests.
GitOrigin-RevId: ed67fe5305048bdf283a26ec874337d549e3324f