## Why
Awaiting a bounded consumer event queue can stall the in-process app-server
worker when notifications are not being drained, preventing it from delivering
a request response queued behind them.
## What changed
- Use an unbounded queue for caller-facing in-process events while keeping
command and embedded-runtime queues bounded.
- Preserve all events in order instead of dropping best-effort events and
emitting lag markers when the consumer queue fills.
- Document that callers can await requests without concurrently draining
notifications.
## Testing
Add a regression test that fills a capacity-one client with unread settings
notifications, verifies subsequent requests complete, and then confirms the
notifications remain readable in order.
GitOrigin-RevId: 6ca6cfb9349dfa04a613236836f813c1f799783e
This is a subset of PR #13636. See that PR for a full overview of the
architectural change.
This PR implements the in-process app server and modifies the
non-interactive "exec" entry point to use the app server.
---------
Co-authored-by: Felipe Coury <felipe.coury@gmail.com>
