feat(keybindings): add task switch shortcut preserving panel focus

Cmd+Opt+Left/Right (macOS) and Ctrl+PageUp/PageDown (Linux) jump to the
prev/next task while keeping the focused panel (Chat / Notes / Changed
Files) the same. Falls back to the default panel when the target task
lacks the current panel.

Replaces the dead, mis-semantic `navigateTask` stub in navigation.ts
with a grid-aware version in focus.ts that can validate panel identity
against the target task's layout.

Author: johannesjo

src/App.tsx

@@ -31,6 +31,7 @@ import {
   stopTaskStatusPolling,
   navigateRow,
   navigateColumn,
+  navigateTask,
   setPendingAction,
   toggleHelpDialog,
   toggleSettingsDialog,
@@ -456,6 +457,8 @@ function App() {
       'navigateRow:down': () => navigateRow('down'),
       'navigateColumn:left': () => navigateColumn('left'),
       'navigateColumn:right': () => navigateColumn('right'),
+      'navigateTask:left': () => navigateTask('left'),
+      'navigateTask:right': () => navigateTask('right'),
       'moveActiveTask:left': () => moveActiveTask('left'),
       'moveActiveTask:right': () => moveActiveTask('right'),
       ...Object.fromEntries(

src/lib/keybindings/defaults.ts

@@ -48,6 +48,53 @@ export const DEFAULT_BINDINGS: KeyBinding[] = [
     action: 'navigateColumn:right',
     global: true,
   },
+  // Cmd+Opt+Arrow on macOS (Chrome-style tab switching). On Linux, Ctrl+Alt+Arrow
+  // is captured by GNOME/KDE for workspace switching, so use Ctrl+PageUp/PageDown
+  // instead — same shortcut Chrome and Firefox use for tabs on Linux.
+  {
+    id: 'app.nav.task-left',
+    layer: 'app',
+    category: 'Navigation',
+    description: 'Switch to previous task',
+    platform: 'mac',
+    key: 'ArrowLeft',
+    modifiers: { cmdOrCtrl: true, alt: true },
+    action: 'navigateTask:left',
+    global: true,
+  },
+  {
+    id: 'app.nav.task-right',
+    layer: 'app',
+    category: 'Navigation',
+    description: 'Switch to next task',
+    platform: 'mac',
+    key: 'ArrowRight',
+    modifiers: { cmdOrCtrl: true, alt: true },
+    action: 'navigateTask:right',
+    global: true,
+  },
+  {
+    id: 'app.nav.task-left-linux',
+    layer: 'app',
+    category: 'Navigation',
+    description: 'Switch to previous task',
+    platform: 'linux',
+    key: 'PageUp',
+    modifiers: { cmdOrCtrl: true },
+    action: 'navigateTask:left',
+    global: true,
+  },
+  {
+    id: 'app.nav.task-right-linux',
+    layer: 'app',
+    category: 'Navigation',
+    description: 'Switch to next task',
+    platform: 'linux',
+    key: 'PageDown',
+    modifiers: { cmdOrCtrl: true },
+    action: 'navigateTask:right',
+    global: true,
+  },
 
   // -------------------------------------------------------------------------
   // App layer — Task reordering

src/store/focus.test.ts

@@ -82,7 +82,7 @@ vi.mock('./tasks', () => ({
   }),
 }));
 
-import { navigateColumn, navigateRow } from './focus';
+import { navigateColumn, navigateRow, navigateTask } from './focus';
 
 function setTask(id: string, overrides: Record<string, unknown> = {}): void {
   mockStore.tasks[id] = {
@@ -223,3 +223,92 @@ describe('focus navigation neighbor map', () => {
     expect(mockStore.focusedPanel['task-1']).toBe('shell:0');
   });
 });
+
+describe('navigateTask', () => {
+  it('preserves the focused panel name when switching to the next task', () => {
+    setTask('task-1');
+    setTask('task-2');
+    mockStore.taskOrder = ['task-1', 'task-2'];
+    mockStore.focusedPanel['task-1'] = 'changed-files';
+
+    navigateTask('right');
+
+    expect(mockStore.activeTaskId).toBe('task-2');
+    expect(mockStore.focusedPanel['task-2']).toBe('changed-files');
+  });
+
+  it('preserves the focused panel name when switching to the previous task', () => {
+    setTask('task-1');
+    setTask('task-2');
+    mockStore.taskOrder = ['task-1', 'task-2'];
+    mockStore.activeTaskId = 'task-2';
+    mockStore.focusedPanel['task-2'] = 'notes';
+
+    navigateTask('left');
+
+    expect(mockStore.activeTaskId).toBe('task-1');
+    expect(mockStore.focusedPanel['task-1']).toBe('notes');
+  });
+
+  it('falls back to the default panel when the current panel does not exist in the target', () => {
+    setTask('task-1', { stepsEnabled: true, stepsContent: [{ id: 'step-1' }] });
+    setTask('task-2');
+    mockStore.taskOrder = ['task-1', 'task-2'];
+    mockStore.focusedPanel['task-1'] = 'steps';
+
+    navigateTask('right');
+
+    expect(mockStore.activeTaskId).toBe('task-2');
+    expect(mockStore.focusedPanel['task-2']).toBe('ai-terminal');
+  });
+
+  it('is a no-op at the leftmost task', () => {
+    setTask('task-1');
+    setTask('task-2');
+    mockStore.taskOrder = ['task-1', 'task-2'];
+    mockStore.activeTaskId = 'task-1';
+    mockStore.focusedPanel['task-1'] = 'changed-files';
+
+    navigateTask('left');
+
+    expect(mockStore.activeTaskId).toBe('task-1');
+    expect(mockStore.focusedPanel['task-1']).toBe('changed-files');
+    expect(mockStore.sidebarFocused).toBe(false);
+  });
+
+  it('is a no-op at the rightmost task', () => {
+    setTask('task-1');
+    setTask('task-2');
+    mockStore.taskOrder = ['task-1', 'task-2'];
+    mockStore.activeTaskId = 'task-2';
+    mockStore.focusedPanel['task-2'] = 'notes';
+
+    navigateTask('right');
+
+    expect(mockStore.activeTaskId).toBe('task-2');
+    expect(mockStore.focusedPanel['task-2']).toBe('notes');
+    expect(mockStore.placeholderFocused).toBe(false);
+  });
+
+  it('is a no-op when the active id is not in taskOrder (e.g. terminal)', () => {
+    setTask('task-1');
+    mockStore.taskOrder = ['task-1'];
+    mockStore.activeTaskId = 'terminal-1';
+
+    navigateTask('right');
+
+    expect(mockStore.activeTaskId).toBe('terminal-1');
+  });
+
+  it('is a no-op while a dialog is open', () => {
+    setTask('task-1');
+    setTask('task-2');
+    mockStore.taskOrder = ['task-1', 'task-2'];
+    mockStore.focusedPanel['task-1'] = 'changed-files';
+    mockStore.showHelpDialog = true;
+
+    navigateTask('right');
+
+    expect(mockStore.activeTaskId).toBe('task-1');
+  });
+});

src/store/focus.ts

@@ -401,6 +401,38 @@ export function navigateColumn(direction: 'left' | 'right'): void {
   }
 }
 
+/**
+ * Switch directly to the prev/next task in `taskOrder`, preserving the focused
+ * panel name when it exists in the target's grid. Clamps at edges (no sidebar
+ * or placeholder fall-through). Collapsed tasks are not in `taskOrder`, so
+ * they are skipped — same semantics as `navigateColumn`'s cross-task path.
+ */
+export function navigateTask(direction: 'left' | 'right'): void {
+  if (store.showNewTaskDialog || store.showHelpDialog || store.showSettingsDialog) return;
+
+  const { taskOrder, activeTaskId } = store;
+  if (!activeTaskId) return;
+
+  const currentIdx = taskOrder.indexOf(activeTaskId);
+  if (currentIdx === -1) return;
+
+  const targetIdx = direction === 'left' ? currentIdx - 1 : currentIdx + 1;
+  if (targetIdx < 0 || targetIdx >= taskOrder.length) return;
+
+  const targetId = taskOrder[targetIdx];
+  if (!store.tasks[targetId]) return;
+
+  const currentPanel = getTaskFocusedPanel(activeTaskId);
+  const targetGrid = buildGrid(targetId);
+  const targetPanel =
+    findInGrid(targetGrid, currentPanel) !== null ? currentPanel : defaultPanelFor(targetId);
+
+  batch(() => {
+    setActiveTask(targetId);
+    setTaskFocusedPanel(targetId, targetPanel);
+  });
+}
+
 export function setPendingAction(
   action: { type: 'close' | 'merge' | 'push'; taskId: string } | null,
 ): void {

src/store/navigation.ts

@@ -16,15 +16,6 @@ export function setActiveAgent(agentId: string): void {
   setStore('activeAgentId', agentId);
 }
 
-export function navigateTask(direction: 'left' | 'right'): void {
-  const { taskOrder, activeTaskId } = store;
-  if (taskOrder.length === 0) return;
-  const idx = activeTaskId ? taskOrder.indexOf(activeTaskId) : -1;
-  const next =
-    direction === 'left' ? Math.max(0, idx - 1) : Math.min(taskOrder.length - 1, idx + 1);
-  setActiveTask(taskOrder[next]);
-}
-
 export function navigateAgent(direction: 'up' | 'down'): void {
   const { activeTaskId, activeAgentId } = store;
   if (!activeTaskId) return;

src/store/store.ts

@@ -58,7 +58,6 @@ export {
 export {
   setActiveTask,
   setActiveAgent,
-  navigateTask,
   navigateAgent,
   moveActiveTask,
   jumpToTask,
@@ -80,6 +79,7 @@ export {
   unfocusPlaceholder,
   navigateRow,
   navigateColumn,
+  navigateTask,
   setPendingAction,
   clearPendingAction,
   toggleHelpDialog,