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/stores/layout.test.ts

@@ -0,0 +1,299 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+
+// Mock session-bridge before importing the layout store
+vi.mock('../adapters/session-bridge', () => ({
+  listSessions: vi.fn().mockResolvedValue([]),
+  saveSession: vi.fn().mockResolvedValue(undefined),
+  deleteSession: vi.fn().mockResolvedValue(undefined),
+  updateSessionTitle: vi.fn().mockResolvedValue(undefined),
+  touchSession: vi.fn().mockResolvedValue(undefined),
+  saveLayout: vi.fn().mockResolvedValue(undefined),
+  loadLayout: vi.fn().mockResolvedValue({ preset: '1-col', pane_ids: [] }),
+}));
+
+import {
+  getPanes,
+  getActivePreset,
+  getFocusedPaneId,
+  addPane,
+  removePane,
+  focusPane,
+  focusPaneByIndex,
+  setPreset,
+  renamePaneTitle,
+  getGridTemplate,
+  getPaneGridArea,
+  type LayoutPreset,
+  type Pane,
+} from './layout.svelte';
+
+// Helper to reset module state between tests
+// The layout store uses module-level $state, so we need to clean up
+function clearAllPanes(): void {
+  const panes = getPanes();
+  const ids = panes.map(p => p.id);
+  for (const id of ids) {
+    removePane(id);
+  }
+}
+
+beforeEach(() => {
+  clearAllPanes();
+  setPreset('1-col');
+  vi.clearAllMocks();
+});
+
+describe('layout store', () => {
+  describe('addPane', () => {
+    it('adds a pane to the list', () => {
+      addPane({ id: 'p1', type: 'terminal', title: 'Terminal 1' });
+
+      const panes = getPanes();
+      expect(panes).toHaveLength(1);
+      expect(panes[0].id).toBe('p1');
+      expect(panes[0].type).toBe('terminal');
+      expect(panes[0].title).toBe('Terminal 1');
+    });
+
+    it('sets focused to false initially then focuses via focusPane', () => {
+      addPane({ id: 'p1', type: 'terminal', title: 'T1' });
+
+      // addPane calls focusPane internally, so the pane should be focused
+      expect(getFocusedPaneId()).toBe('p1');
+      const panes = getPanes();
+      expect(panes[0].focused).toBe(true);
+    });
+
+    it('focuses the newly added pane', () => {
+      addPane({ id: 'p1', type: 'terminal', title: 'T1' });
+      addPane({ id: 'p2', type: 'agent', title: 'Agent 1' });
+
+      expect(getFocusedPaneId()).toBe('p2');
+    });
+
+    it('calls autoPreset when adding panes', () => {
+      // 1 pane -> 1-col
+      addPane({ id: 'p1', type: 'terminal', title: 'T1' });
+      expect(getActivePreset()).toBe('1-col');
+
+      // 2 panes -> 2-col
+      addPane({ id: 'p2', type: 'terminal', title: 'T2' });
+      expect(getActivePreset()).toBe('2-col');
+
+      // 3 panes -> master-stack
+      addPane({ id: 'p3', type: 'terminal', title: 'T3' });
+      expect(getActivePreset()).toBe('master-stack');
+
+      // 4+ panes -> 2x2
+      addPane({ id: 'p4', type: 'terminal', title: 'T4' });
+      expect(getActivePreset()).toBe('2x2');
+    });
+  });
+
+  describe('removePane', () => {
+    it('removes a pane by id', () => {
+      addPane({ id: 'p1', type: 'terminal', title: 'T1' });
+      addPane({ id: 'p2', type: 'terminal', title: 'T2' });
+
+      removePane('p1');
+
+      const panes = getPanes();
+      expect(panes).toHaveLength(1);
+      expect(panes[0].id).toBe('p2');
+    });
+
+    it('focuses the first remaining pane when focused pane is removed', () => {
+      addPane({ id: 'p1', type: 'terminal', title: 'T1' });
+      addPane({ id: 'p2', type: 'terminal', title: 'T2' });
+      addPane({ id: 'p3', type: 'terminal', title: 'T3' });
+
+      // p3 is focused (last added)
+      expect(getFocusedPaneId()).toBe('p3');
+
+      removePane('p3');
+
+      // Should focus p1 (first remaining)
+      expect(getFocusedPaneId()).toBe('p1');
+    });
+
+    it('sets focusedPaneId to null when last pane is removed', () => {
+      addPane({ id: 'p1', type: 'terminal', title: 'T1' });
+      removePane('p1');
+
+      expect(getFocusedPaneId()).toBeNull();
+    });
+
+    it('adjusts preset via autoPreset after removal', () => {
+      addPane({ id: 'p1', type: 'terminal', title: 'T1' });
+      addPane({ id: 'p2', type: 'terminal', title: 'T2' });
+      expect(getActivePreset()).toBe('2-col');
+
+      removePane('p2');
+      expect(getActivePreset()).toBe('1-col');
+    });
+
+    it('does not change focus if removed pane was not focused', () => {
+      addPane({ id: 'p1', type: 'terminal', title: 'T1' });
+      addPane({ id: 'p2', type: 'terminal', title: 'T2' });
+
+      // p2 is focused (last added). Remove p1
+      focusPane('p2');
+      removePane('p1');
+
+      expect(getFocusedPaneId()).toBe('p2');
+    });
+  });
+
+  describe('focusPane', () => {
+    it('sets focused flag on the target pane', () => {
+      addPane({ id: 'p1', type: 'terminal', title: 'T1' });
+      addPane({ id: 'p2', type: 'terminal', title: 'T2' });
+
+      focusPane('p1');
+
+      const panes = getPanes();
+      expect(panes.find(p => p.id === 'p1')?.focused).toBe(true);
+      expect(panes.find(p => p.id === 'p2')?.focused).toBe(false);
+      expect(getFocusedPaneId()).toBe('p1');
+    });
+  });
+
+  describe('focusPaneByIndex', () => {
+    it('focuses pane at the given index', () => {
+      addPane({ id: 'p1', type: 'terminal', title: 'T1' });
+      addPane({ id: 'p2', type: 'terminal', title: 'T2' });
+
+      focusPaneByIndex(0);
+
+      expect(getFocusedPaneId()).toBe('p1');
+    });
+
+    it('ignores out-of-bounds indices', () => {
+      addPane({ id: 'p1', type: 'terminal', title: 'T1' });
+
+      focusPaneByIndex(5);
+
+      // Should remain on p1
+      expect(getFocusedPaneId()).toBe('p1');
+    });
+
+    it('ignores negative indices', () => {
+      addPane({ id: 'p1', type: 'terminal', title: 'T1' });
+
+      focusPaneByIndex(-1);
+
+      expect(getFocusedPaneId()).toBe('p1');
+    });
+  });
+
+  describe('setPreset', () => {
+    it('overrides the active preset', () => {
+      setPreset('3-col');
+      expect(getActivePreset()).toBe('3-col');
+    });
+
+    it('allows setting any valid preset', () => {
+      const presets: LayoutPreset[] = ['1-col', '2-col', '3-col', '2x2', 'master-stack'];
+      for (const preset of presets) {
+        setPreset(preset);
+        expect(getActivePreset()).toBe(preset);
+      }
+    });
+  });
+
+  describe('renamePaneTitle', () => {
+    it('updates the title of a pane', () => {
+      addPane({ id: 'p1', type: 'terminal', title: 'Old Title' });
+
+      renamePaneTitle('p1', 'New Title');
+
+      const panes = getPanes();
+      expect(panes[0].title).toBe('New Title');
+    });
+
+    it('does nothing for non-existent pane', () => {
+      addPane({ id: 'p1', type: 'terminal', title: 'Title' });
+
+      renamePaneTitle('p-nonexistent', 'New Title');
+
+      expect(getPanes()[0].title).toBe('Title');
+    });
+  });
+
+  describe('getGridTemplate', () => {
+    it('returns 1fr / 1fr for 1-col', () => {
+      setPreset('1-col');
+      expect(getGridTemplate()).toEqual({ columns: '1fr', rows: '1fr' });
+    });
+
+    it('returns 1fr 1fr / 1fr for 2-col', () => {
+      setPreset('2-col');
+      expect(getGridTemplate()).toEqual({ columns: '1fr 1fr', rows: '1fr' });
+    });
+
+    it('returns 1fr 1fr 1fr / 1fr for 3-col', () => {
+      setPreset('3-col');
+      expect(getGridTemplate()).toEqual({ columns: '1fr 1fr 1fr', rows: '1fr' });
+    });
+
+    it('returns 1fr 1fr / 1fr 1fr for 2x2', () => {
+      setPreset('2x2');
+      expect(getGridTemplate()).toEqual({ columns: '1fr 1fr', rows: '1fr 1fr' });
+    });
+
+    it('returns 2fr 1fr / 1fr 1fr for master-stack', () => {
+      setPreset('master-stack');
+      expect(getGridTemplate()).toEqual({ columns: '2fr 1fr', rows: '1fr 1fr' });
+    });
+  });
+
+  describe('getPaneGridArea', () => {
+    it('returns grid area for first pane in master-stack', () => {
+      setPreset('master-stack');
+      expect(getPaneGridArea(0)).toBe('1 / 1 / 3 / 2');
+    });
+
+    it('returns undefined for non-first panes in master-stack', () => {
+      setPreset('master-stack');
+      expect(getPaneGridArea(1)).toBeUndefined();
+      expect(getPaneGridArea(2)).toBeUndefined();
+    });
+
+    it('returns undefined for all panes in non-master-stack presets', () => {
+      setPreset('2-col');
+      expect(getPaneGridArea(0)).toBeUndefined();
+      expect(getPaneGridArea(1)).toBeUndefined();
+    });
+  });
+
+  describe('autoPreset behavior', () => {
+    it('0 panes -> 1-col', () => {
+      expect(getActivePreset()).toBe('1-col');
+    });
+
+    it('1 pane -> 1-col', () => {
+      addPane({ id: 'p1', type: 'terminal', title: 'T1' });
+      expect(getActivePreset()).toBe('1-col');
+    });
+
+    it('2 panes -> 2-col', () => {
+      addPane({ id: 'p1', type: 'terminal', title: 'T1' });
+      addPane({ id: 'p2', type: 'terminal', title: 'T2' });
+      expect(getActivePreset()).toBe('2-col');
+    });
+
+    it('3 panes -> master-stack', () => {
+      addPane({ id: 'p1', type: 'terminal', title: 'T1' });
+      addPane({ id: 'p2', type: 'terminal', title: 'T2' });
+      addPane({ id: 'p3', type: 'terminal', title: 'T3' });
+      expect(getActivePreset()).toBe('master-stack');
+    });
+
+    it('4+ panes -> 2x2', () => {
+      for (let i = 1; i <= 5; i++) {
+        addPane({ id: `p${i}`, type: 'terminal', title: `T${i}` });
+      }
+      expect(getActivePreset()).toBe('2x2');
+    });
+  });
+});