Add Storybook story for AppBar component

Mocks @tauri-apps/api/window via a Vite alias in viteFinal so the
module-level getCurrentWindow() call doesn't crash Storybook. Stories
cover the main content variants: default, home dir, long path, single
shell, many shells, and path outside home.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: nedtwigg

lib/.storybook/main.ts

@@ -3,6 +3,14 @@ import type { StorybookConfig } from '@storybook/react-vite';
 const config: StorybookConfig = {
   stories: ['../src/**/*.stories.@(ts|tsx)'],
   framework: '@storybook/react-vite',
+  viteFinal: (config) => {
+    config.resolve ??= {};
+    config.resolve.alias = {
+      ...(config.resolve.alias as Record<string, string> ?? {}),
+      '@tauri-apps/api/window': new URL('./tauri-window-mock.ts', import.meta.url).pathname,
+    };
+    return config;
+  },
 };
 
 export default config;

lib/.storybook/tauri-window-mock.ts

@@ -0,0 +1,11 @@
+const mockWindow = {
+  isMaximized: () => Promise.resolve(false),
+  onResized: (_callback: () => void) => Promise.resolve(() => {}),
+  minimize: () => Promise.resolve(),
+  toggleMaximize: () => Promise.resolve(),
+  close: () => Promise.resolve(),
+};
+
+export function getCurrentWindow() {
+  return mockWindow;
+}

lib/src/stories/AppBar.stories.tsx

@@ -0,0 +1,70 @@
+import type { Meta, StoryObj } from '@storybook/react';
+import { AppBar } from '../../../standalone/src/AppBar';
+
+const DEFAULT_SHELLS = [
+  { name: 'bash', path: '/bin/bash' },
+  { name: 'zsh', path: '/bin/zsh' },
+  { name: 'fish', path: '/usr/bin/fish' },
+];
+
+function AppBarStory(props: React.ComponentProps<typeof AppBar>) {
+  return (
+    <div style={{ width: '100%' }}>
+      <AppBar {...props} />
+    </div>
+  );
+}
+
+const meta: Meta<typeof AppBarStory> = {
+  title: 'Components/AppBar',
+  component: AppBarStory,
+  args: {
+    projectDir: '/home/user/projects/mouseterm',
+    homeDir: '/home/user',
+    shells: DEFAULT_SHELLS,
+  },
+};
+
+export default meta;
+type Story = StoryObj<typeof AppBarStory>;
+
+export const Default: Story = {};
+
+export const HomeDirectory: Story = {
+  args: {
+    projectDir: '/home/user',
+    homeDir: '/home/user',
+  },
+};
+
+export const LongPath: Story = {
+  args: {
+    projectDir: '/home/user/projects/very-deep/nested/directory/structure/my-project',
+    homeDir: '/home/user',
+  },
+};
+
+export const SingleShell: Story = {
+  args: {
+    shells: [{ name: 'bash', path: '/bin/bash' }],
+  },
+};
+
+export const ManyShells: Story = {
+  args: {
+    shells: [
+      { name: 'bash', path: '/bin/bash' },
+      { name: 'zsh', path: '/bin/zsh' },
+      { name: 'fish', path: '/usr/bin/fish' },
+      { name: 'sh', path: '/bin/sh' },
+      { name: 'nu', path: '/usr/bin/nu' },
+    ],
+  },
+};
+
+export const AbsolutePathOutsideHome: Story = {
+  args: {
+    projectDir: '/var/www/my-site',
+    homeDir: '/home/user',
+  },
+};