perf: optimize app startup and background lifecycles

tests/unit/agent-browser-core.test.ts

@@ -478,10 +478,6 @@ describe('AgentBrowserModule', () => {
     expect(view.webContents.debugger.operationLog).toEqual([
       'load:about:blank',
       'attach:1.3',
-      'command:Runtime.enable',
-      'command:Log.enable',
-      'command:Network.enable',
-      'command:Page.enable',
       'command:Target.setAutoAttach',
       'load:http://127.0.0.1:4173/',
     ]);
@@ -662,11 +658,22 @@ describe('AgentBrowserModule', () => {
       projectPath,
       url: 'http://localhost:3000',
     });
+    const view = adapter.views[0];
+    if (!view) throw new Error('browser view was not created');
     await module.present({
       projectPath,
       visible: true,
       bounds: { x: 0, y: 0, width: 800, height: 600 },
     });
+    await module.setDiagnostics({ projectPath, enabled: true });
+    view.webContents.debugger.message('Runtime.consoleAPICalled', {
+      type: 'log',
+      args: [{ value: 'ready' }],
+    });
+    view.webContents.debugger.message('Network.requestWillBeSent', {
+      requestId: 'request-1',
+      request: { url: 'http://localhost:3000/api/data' },
+    });
 
     const page = await module.readEvents({ projectPath, after: 0 });
     expect(page.events.map((event) => event.method)).toEqual([
@@ -863,6 +870,7 @@ describe('AgentBrowserModule', () => {
 
   it('moves oversized events and command results into bounded payload handles', async () => {
     const { module, view } = await openBrowser();
+    await module.setDiagnostics({ projectPath, enabled: true });
     const largeText = 'x'.repeat(70 * 1024);
     view.webContents.debugger.message('Network.dataReceived', { data: largeText });
 
@@ -905,6 +913,7 @@ describe('AgentBrowserModule', () => {
 
   it('reports a debugger gap and reattaches with a new generation after DevTools closes', async () => {
     const { module, view } = await openBrowser();
+    await module.setDiagnostics({ projectPath, enabled: true });
     view.webContents.debugger.message('Runtime.consoleAPICalled', { type: 'log' });
     const before = await module.readEvents({ projectPath, after: 0 });