fix(web-server): run usage cleanup during dashboard shutdown

- pass server cleanup callback into graceful shutdown wiring

- stop usage aggregator background sync when config server exits

- prevent orphaned sync intervals across dashboard restarts

src/commands/config-command.ts

@@ -160,10 +160,10 @@ export async function handleConfigCommand(args: string[]): Promise<void> {
 
   try {
     // Start server
-    const { server, wss } = await startServer({ port, dev: options.dev });
+    const { server, wss, cleanup } = await startServer({ port, dev: options.dev });
 
     // Setup graceful shutdown
-    setupGracefulShutdown(server, wss);
+    setupGracefulShutdown(server, wss, cleanup);
 
     const url = `http://localhost:${port}`;
 

src/web-server/index.ts

@@ -13,6 +13,7 @@ import { WebSocketServer } from 'ws';
 import { setupWebSocket } from './websocket';
 import { createSessionMiddleware, authMiddleware } from './middleware/auth-middleware';
 import { startAutoSyncWatcher, stopAutoSyncWatcher } from '../cliproxy/sync';
+import { shutdownUsageAggregator } from './usage/aggregator';
 
 export interface ServerOptions {
   port: number;
@@ -107,6 +108,7 @@ export async function startServer(options: ServerOptions): Promise<ServerInstanc
   const cleanup = () => {
     wsCleanup();
     stopAutoSyncWatcher().catch(() => {});
+    shutdownUsageAggregator();
   };
 
   // Start listening