## Why
Thread startup, running-thread resume, and rollback could outlive their request handlers, allowing connection draining and request serialization to finish too early.
## What changed
- Await thread startup and listener completion for running-thread resume and rollback.
- Release the thread-list permit before waiting for resume completion so the listener can finish rollback responses.
- Release pending rollback waiters when clearing a listener, and discard queued requests when their connection closes.
## Testing
Add coverage for releasing queued requests and rollback waiters, and pipeline resume during rollback to check that both responses complete. Update diagnostics expectations to allow startup to remain in flight after its response is queued.
GitOrigin-RevId: 138156179afbc40de29965820db7fa9cd3669cc7
## What changed
- Add lifecycle-backed gauges for in-flight and queued app requests, pending server requests and mailbox messages, active turns, and live MCP connections.
- Register each gauge on first use and decrement it when the tracked work or resource is dropped.
- Document the new `server/diagnostics` gauge names and account for the diagnostics request itself in the response example and test.
GitOrigin-RevId: 4bb82a3918af0b502d149b5d761ad669b2083f39
## What changed
- Add the experimental `server/diagnostics` request, returning the app-server process ID, resident memory, platform-dependent physical footprint, and registered diagnostic gauges.
- Export the new protocol types in the generated JSON and TypeScript schemas and document the request.
## Testing
- Verify the response includes process measurements and the registered live-thread gauge.
- Verify the request is rejected unless `capabilities.experimentalApi` is enabled.
GitOrigin-RevId: 099d60a9c421a74ff1a72fe524e0dfeb89cf1057
Eric Traut