[codex] Handle chat run abort lifecycle (#454)

* feat: call upstream stop API when aborting a run

- Modified handleAbort to call POST /v1/runs/{run_id}/stop endpoint
- Use profile-specific upstream URL and API key from gatewayManager
- Add 5-second timeout with error handling and logging
- Keep local abortController.abort() for EventSource cleanup
- Change handleAbort to async method and update call site

This ensures the upstream Hermes gateway is properly notified
when a user aborts a run, allowing graceful termination.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* fix: close ChatRunSocket connections on shutdown to prevent hanging

- Add close() method to ChatRunSocket to abort all active runs
  and clear session state
- Pass chatRunServer to bindShutdown and close it before
  groupChatServer during shutdown
- This prevents EventSource connections and abort controllers
  from keeping the process alive during nodemon restart

Fixes the "still waiting for sub-process to finish" issue.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* Handle chat run abort lifecycle

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/server/src/services/shutdown.ts

@@ -1,6 +1,6 @@
 import { logger } from './logger'
 
-export function bindShutdown(server: any, groupChatServer?: any): void {
+export function bindShutdown(server: any, groupChatServer?: any, chatRunServer?: any): void {
   let isShuttingDown = false
 
   const shutdown = async (signal: string) => {
@@ -10,6 +10,12 @@ export function bindShutdown(server: any, groupChatServer?: any): void {
     logger.info('Shutting down (%s)...', signal)
 
     try {
+      // Close ChatRunSocket first to abort all active runs and close EventSource connections
+      if (chatRunServer) {
+        chatRunServer.close()
+        logger.info('ChatRunSocket closed')
+      }
+
       // Disconnect Socket.IO before HTTP server to prevent hanging
       if (groupChatServer) {
         groupChatServer.agentClients.disconnectAll()