The append method created a new WriteStream for every log chunk and resolved
the promise on the end callback (data flushed) rather than the close event
(fd released). Over many agent runs the leaked fds corrupted the fd table,
causing child_process.spawn to fail with EBADF.
Replace with fs.appendFile which properly opens, writes, and closes the fd
before resolving.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Expand heartbeat service with full run executor, wakeup coordinator,
and adapter lifecycle. Add run-log-store for pluggable log persistence.
Add live-events service and WebSocket handler for realtime updates.
Expand agent and issue routes with runtime operations. Add ws dependency.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
