perf: optimize app startup and background lifecycles

src/lib/agent-browser.ts

@@ -122,6 +122,20 @@ export async function presentAgentBrowser(input: {
   return requireSuccess(response).browser;
 }
 
+export async function setAgentBrowserDiagnostics(input: {
+  projectPath: string;
+  enabled: boolean;
+}): Promise<AgentBrowserSnapshot> {
+  const response = await hostApiFetch<BrowserEnvelope>(
+    '/api/agent-browser/diagnostics',
+    jsonBody({
+      project_path: input.projectPath,
+      enabled: input.enabled,
+    }),
+  );
+  return requireSuccess(response).browser;
+}
+
 export async function navigateAgentBrowser(input: {
   projectPath: string;
   action: AgentBrowserNavigateAction;