fix: resolve server.close recursion, add MV3 keep-alive ping, and clean up Windows port kill

src/context.ts

@@ -17,10 +17,14 @@ export class Context {
     return this._ws;
   }
 
-  set ws(ws: WebSocket) {
+  set ws(ws: WebSocket | undefined) {
     this._ws = ws;
   }
 
+  clearWs() {
+    this._ws = undefined;
+  }
+
   hasWs(): boolean {
     return !!this._ws;
   }
@@ -48,5 +52,6 @@ export class Context {
       return;
     }
     await this._ws.close();
+    this._ws = undefined;
   }
 }

src/server.ts

@@ -35,9 +35,27 @@ export async function createServerWithTools(options: Options): Promise<Server> {
   wss.on("connection", (websocket) => {
     // Close any existing connections
     if (context.hasWs()) {
-      context.ws.close();
+      try {
+        context.ws.close();
+      } catch {}
     }
     context.ws = websocket;
+
+    // Ping heartbeat to keep Chrome MV3 background service worker alive
+    const pingInterval = setInterval(() => {
+      if (websocket.readyState === websocket.OPEN) {
+        websocket.ping();
+      } else {
+        clearInterval(pingInterval);
+      }
+    }, 5000);
+
+    websocket.on("close", () => {
+      clearInterval(pingInterval);
+      if (context.hasWs() && context.ws === websocket) {
+        context.clearWs();
+      }
+    });
   });
 
   server.setRequestHandler(ListToolsRequestSchema, async () => {
@@ -82,8 +100,9 @@ export async function createServerWithTools(options: Options): Promise<Server> {
     return { contents };
   });
 
+  const originalClose = server.close.bind(server);
   server.close = async () => {
-    await server.close();
+    await originalClose();
     await wss.close();
     await context.close();
   };

src/utils/port.ts

@@ -16,12 +16,15 @@ export function killProcessOnPort(port: number) {
   try {
     if (process.platform === "win32") {
       execSync(
-        `FOR /F "tokens=5" %a in ('netstat -ano ^| findstr :${port}') do taskkill /F /PID %a`,
+        `FOR /F "tokens=5" %a in ('netstat -ano ^| findstr :${port}') do taskkill /F /PID %a 2>nul`,
+        { stdio: "ignore" },
       );
     } else {
-      execSync(`lsof -ti:${port} | xargs kill -9`);
+      execSync(`lsof -ti:${port} | xargs kill -9 2>/dev/null`, {
+        stdio: "ignore",
+      });
     }
-  } catch (error) {
-    console.error(`Failed to kill process on port ${port}:`, error);
+  } catch {
+    // Port might not be in use, ignore expected exit code
   }
 }