test(v2): add integration tests for layout, agent-bridge, and dispatcher

Add 59 new vitest tests: layout.test.ts (30), agent-bridge.test.ts (11),
agent-dispatcher.test.ts (18). Fix unused import in sdk-messages.test.ts.
Add WebDriver E2E scaffold README. Total: 104 vitest + 29 cargo tests.

v2/src/lib/adapters/agent-bridge.test.ts

@@ -0,0 +1,170 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+
+// Use vi.hoisted to declare mocks that are accessible inside vi.mock factories
+const { mockInvoke, mockListen } = vi.hoisted(() => ({
+  mockInvoke: vi.fn(),
+  mockListen: vi.fn(),
+}));
+
+vi.mock('@tauri-apps/api/core', () => ({
+  invoke: mockInvoke,
+}));
+
+vi.mock('@tauri-apps/api/event', () => ({
+  listen: mockListen,
+}));
+
+import {
+  queryAgent,
+  stopAgent,
+  isAgentReady,
+  restartAgent,
+  onSidecarMessage,
+  onSidecarExited,
+  type AgentQueryOptions,
+} from './agent-bridge';
+
+beforeEach(() => {
+  vi.clearAllMocks();
+});
+
+describe('agent-bridge', () => {
+  describe('queryAgent', () => {
+    it('invokes agent_query with options', async () => {
+      mockInvoke.mockResolvedValue(undefined);
+
+      const options: AgentQueryOptions = {
+        session_id: 'sess-1',
+        prompt: 'Hello Claude',
+        cwd: '/tmp',
+        max_turns: 10,
+        max_budget_usd: 1.0,
+      };
+
+      await queryAgent(options);
+
+      expect(mockInvoke).toHaveBeenCalledWith('agent_query', { options });
+    });
+
+    it('passes minimal options (only required fields)', async () => {
+      mockInvoke.mockResolvedValue(undefined);
+
+      const options: AgentQueryOptions = {
+        session_id: 'sess-2',
+        prompt: 'Do something',
+      };
+
+      await queryAgent(options);
+
+      expect(mockInvoke).toHaveBeenCalledWith('agent_query', { options });
+    });
+
+    it('propagates invoke errors', async () => {
+      mockInvoke.mockRejectedValue(new Error('Sidecar not running'));
+
+      await expect(
+        queryAgent({ session_id: 'sess-3', prompt: 'test' }),
+      ).rejects.toThrow('Sidecar not running');
+    });
+  });
+
+  describe('stopAgent', () => {
+    it('invokes agent_stop with session ID', async () => {
+      mockInvoke.mockResolvedValue(undefined);
+
+      await stopAgent('sess-1');
+
+      expect(mockInvoke).toHaveBeenCalledWith('agent_stop', { sessionId: 'sess-1' });
+    });
+  });
+
+  describe('isAgentReady', () => {
+    it('returns true when sidecar is ready', async () => {
+      mockInvoke.mockResolvedValue(true);
+
+      const result = await isAgentReady();
+
+      expect(result).toBe(true);
+      expect(mockInvoke).toHaveBeenCalledWith('agent_ready');
+    });
+
+    it('returns false when sidecar is not ready', async () => {
+      mockInvoke.mockResolvedValue(false);
+
+      const result = await isAgentReady();
+
+      expect(result).toBe(false);
+    });
+  });
+
+  describe('restartAgent', () => {
+    it('invokes agent_restart', async () => {
+      mockInvoke.mockResolvedValue(undefined);
+
+      await restartAgent();
+
+      expect(mockInvoke).toHaveBeenCalledWith('agent_restart');
+    });
+  });
+
+  describe('onSidecarMessage', () => {
+    it('registers listener on sidecar-message event', async () => {
+      const unlisten = vi.fn();
+      mockListen.mockResolvedValue(unlisten);
+
+      const callback = vi.fn();
+      const result = await onSidecarMessage(callback);
+
+      expect(mockListen).toHaveBeenCalledWith('sidecar-message', expect.any(Function));
+      expect(result).toBe(unlisten);
+    });
+
+    it('extracts payload and passes to callback', async () => {
+      mockListen.mockImplementation(async (_event: string, handler: (e: unknown) => void) => {
+        // Simulate Tauri event delivery
+        handler({
+          payload: {
+            type: 'agent_event',
+            sessionId: 'sess-1',
+            event: { type: 'system', subtype: 'init' },
+          },
+        });
+        return vi.fn();
+      });
+
+      const callback = vi.fn();
+      await onSidecarMessage(callback);
+
+      expect(callback).toHaveBeenCalledWith({
+        type: 'agent_event',
+        sessionId: 'sess-1',
+        event: { type: 'system', subtype: 'init' },
+      });
+    });
+  });
+
+  describe('onSidecarExited', () => {
+    it('registers listener on sidecar-exited event', async () => {
+      const unlisten = vi.fn();
+      mockListen.mockResolvedValue(unlisten);
+
+      const callback = vi.fn();
+      const result = await onSidecarExited(callback);
+
+      expect(mockListen).toHaveBeenCalledWith('sidecar-exited', expect.any(Function));
+      expect(result).toBe(unlisten);
+    });
+
+    it('invokes callback without arguments on exit', async () => {
+      mockListen.mockImplementation(async (_event: string, handler: () => void) => {
+        handler();
+        return vi.fn();
+      });
+
+      const callback = vi.fn();
+      await onSidecarExited(callback);
+
+      expect(callback).toHaveBeenCalledWith();
+    });
+  });
+});

v2/src/lib/adapters/sdk-messages.test.ts

@@ -1,6 +1,6 @@
 import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { adaptSDKMessage } from './sdk-messages';
-import type { InitContent, TextContent, ThinkingContent, ToolCallContent, ToolResultContent, StatusContent, CostContent, ErrorContent } from './sdk-messages';
+import type { InitContent, TextContent, ThinkingContent, ToolCallContent, ToolResultContent, StatusContent, CostContent } from './sdk-messages';
 
 // Mock crypto.randomUUID for deterministic IDs when uuid is missing
 beforeEach(() => {