fix(browser): reveal panel for agent captures

Fixes #3175

packages/ui/src/components/layout/ContextPanel.tsx

@@ -452,13 +452,12 @@ export const ContextPanel: React.FC = () => {
 
   // Lets an agent's browser.open create the tab it needs when none is open yet.
   // Registered from the panel because opening a tab is panel state, not
-  // something the browser view itself can do before it exists. Background on
-  // purpose: an agent working a page must not pop the panel open (or steal
-  // the active surface) under the user — the tab mounts invisibly, and the
-  // rail is where the user opens it when curious.
+  // something the browser view itself can do before it exists. Reveal the
+  // panel so Electron gives the webview a composited surface; capturePage()
+  // cannot capture the zero-width webview inside a closed panel.
   React.useEffect(() => {
     if (!effectiveDirectory) return;
-    return registerBrowserOpener((url) => openContextBrowser(effectiveDirectory, url, { reveal: false }));
+    return registerBrowserOpener((url) => openContextBrowser(effectiveDirectory, url));
   }, [effectiveDirectory, openContextBrowser]);
   const reorderContextPanelTabs = useUIStore((state) => state.reorderContextPanelTabs);
   const setSelectedFilePath = useFilesViewTabsStore((state) => state.setSelectedPath);

packages/ui/src/components/layout/__tests__/issue-3175-browserCaptureRevealsPanel.test.ts

@@ -0,0 +1,43 @@
+/**
+ * Regression coverage for https://github.com/openchamber/openchamber/issues/3175
+ *
+ * A full ContextPanel mount is not available in bun test because its import
+ * graph includes a Vite worker URL. This test follows the source-level guard
+ * pattern used by the neighboring ContextPanel regression tests and exercises
+ * the real store behavior that the registered opener delegates to.
+ */
+import { beforeEach, describe, expect, test } from 'bun:test';
+import { readFileSync } from 'node:fs';
+import { dirname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+import { useUIStore } from '@/stores/useUIStore';
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const contextPanelSource = readFileSync(join(__dirname, '..', 'ContextPanel.tsx'), 'utf-8');
+const DIRECTORY = '/path/to/repository';
+
+beforeEach(() => {
+  useUIStore.setState({ contextPanelByDirectory: {}, contextRailOrder: [] });
+});
+
+describe('issue #3175 browser capture while the context panel is closed', () => {
+  test('registers the agent browser opener without suppressing panel reveal', () => {
+    expect(contextPanelSource).toContain(
+      'registerBrowserOpener((url) => openContextBrowser(effectiveDirectory, url))',
+    );
+    expect(contextPanelSource).not.toContain(
+      'openContextBrowser(effectiveDirectory, url, { reveal: false })',
+    );
+  });
+
+  test('opening the agent browser gives its webview a visible panel surface', () => {
+    useUIStore.getState().openContextBrowser(DIRECTORY, 'https://example.com');
+
+    const panel = useUIStore.getState().contextPanelByDirectory[DIRECTORY];
+    expect(panel.isOpen).toBe(true);
+    expect(panel.tabs).toHaveLength(1);
+    expect(panel.tabs[0]?.mode).toBe('browser');
+    expect(panel.tabs[0]?.targetPath).toBe('https://example.com');
+  });
+});