fix(agent-browser): restore bounded presentation lifecycle

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

@@ -1294,6 +1294,76 @@ describe('AgentBrowserModule', () => {
     expect(adapter.views[0].visible).toBe(false);
   });
 
+  it('waits for the matching browser generation to be presented without polling', async () => {
+    const adapter = new FakeAdapter();
+    const module = new AgentBrowserModule(adapter);
+    const opened = await module.open({
+      projectId: 'clock',
+      projectPath,
+      url: 'http://localhost:3000',
+      visible: false,
+    });
+    let settled = false;
+    const presented = module.waitForPresentation({
+      projectPath,
+      generation: opened.generation,
+      timeoutMs: 1_000,
+    }).finally(() => {
+      settled = true;
+    });
+
+    await Promise.resolve();
+    expect(settled).toBe(false);
+    await module.present({
+      projectPath,
+      visible: true,
+      bounds: { x: 1, y: 2, width: 640, height: 480 },
+    });
+
+    await expect(presented).resolves.toMatchObject({
+      state: 'attached',
+      generation: opened.generation,
+      visible: true,
+      bounds: { x: 1, y: 2, width: 640, height: 480 },
+    });
+  });
+
+  it('keeps diagnostics enabled until every explicit owner releases them', async () => {
+    const adapter = new FakeAdapter();
+    const module = new AgentBrowserModule(adapter);
+    await module.open({
+      projectId: 'clock',
+      projectPath,
+      url: 'http://localhost:3000',
+      diagnosticsOwner: 'agent:conversation-a:run-a',
+      visible: true,
+      bounds: { x: 0, y: 0, width: 800, height: 600 },
+    });
+    const commands = adapter.views[0].webContents.debugger.commands;
+    expect(commands.map(({ method }) => method)).toEqual(expect.arrayContaining([
+      'Runtime.enable',
+      'Log.enable',
+      'Network.enable',
+      'Page.enable',
+    ]));
+
+    await module.setDiagnostics({ projectPath, enabled: true, owner: 'renderer' });
+    await module.setDiagnostics({
+      projectPath,
+      enabled: false,
+      owner: 'agent:conversation-a:run-a',
+    });
+    expect(commands.some(({ method }) => method === 'Runtime.disable')).toBe(false);
+
+    await module.setDiagnostics({ projectPath, enabled: false, owner: 'renderer' });
+    expect(commands.map(({ method }) => method)).toEqual(expect.arrayContaining([
+      'Page.disable',
+      'Network.disable',
+      'Log.disable',
+      'Runtime.disable',
+    ]));
+  });
+
   it('tears down the native view when initial navigation fails', async () => {
     const adapter = new FakeAdapter();
     adapter.onCreate = (view) => {