feat(renderer): GitStatusPanel sidebar tab + git.refresh event

src/renderer/components/sidebar/GitStatusPanel.tsx

@@ -0,0 +1,101 @@
+import { useEffect, useState } from 'react';
+import { RefreshCw, FileX, FilePlus, FileEdit, FileQuestion } from 'lucide-react';
+import { Button } from '@/components/ui/button';
+import { useFileStore } from '@/stores/file-store';
+import { ipc } from '@/lib/ipc';
+
+interface GitStatus {
+  filePath: string;
+  status: 'modified' | 'added' | 'deleted' | 'untracked';
+}
+
+const STATUS_ICON: Record<GitStatus['status'], JSX.Element> = {
+  modified: <FileEdit className="h-3 w-3 text-warning" />,
+  added: <FilePlus className="h-3 w-3 text-success" />,
+  deleted: <FileX className="h-3 w-3 text-destructive" />,
+  untracked: <FileQuestion className="h-3 w-3 text-muted-foreground" />,
+};
+
+const STATUS_LABEL: Record<GitStatus['status'], string> = {
+  modified: 'M',
+  added: 'A',
+  deleted: 'D',
+  untracked: '?',
+};
+
+export function GitStatusPanel() {
+  const rootPath = useFileStore((s) => s.rootPath);
+  const openFile = useFileStore((s) => s.openFile);
+  const [status, setStatus] = useState<GitStatus[]>([]);
+  const [error, setError] = useState<string | null>(null);
+  const [loading, setLoading] = useState(false);
+
+  const load = async () => {
+    if (!rootPath) {
+      setStatus([]);
+      return;
+    }
+    setLoading(true);
+    setError(null);
+    const result = await ipc.file.gitStatus({ rootPath });
+    if (!result.ok) {
+      setError(result.error.message);
+      setStatus([]);
+      setLoading(false);
+      return;
+    }
+    setStatus(result.data ?? []);
+    setLoading(false);
+  };
+
+  useEffect(() => {
+    load();
+    // Listen for git.refresh command via custom event
+    const handler = () => load();
+    window.addEventListener('mc:git-refresh', handler);
+    return () => window.removeEventListener('mc:git-refresh', handler);
+  }, [rootPath]);
+
+  if (!rootPath) {
+    return <div className="p-3 text-xs text-muted-foreground">No folder open</div>;
+  }
+
+  if (error) {
+    return (
+      <div className="p-3 text-xs">
+        <div className="text-destructive">Error: {error}</div>
+        <p className="mt-1 text-muted-foreground">Not a git repository, or git not installed.</p>
+        <Button size="sm" variant="ghost" onClick={load} className="mt-2">Retry</Button>
+      </div>
+    );
+  }
+
+  if (status.length === 0 && !loading) {
+    return <div className="p-3 text-xs text-muted-foreground">Working tree clean</div>;
+  }
+
+  return (
+    <div className="p-2 text-xs">
+      <div className="flex items-center justify-between px-1 py-1">
+        <span className="font-semibold">{status.length} changed file{status.length === 1 ? '' : 's'}</span>
+        <Button size="sm" variant="ghost" onClick={load} aria-label="Refresh">
+          <RefreshCw className="h-3 w-3" />
+        </Button>
+      </div>
+      <div className="space-y-0.5">
+        {status.map((s) => (
+          <button
+            key={s.filePath}
+            onClick={() => openFile(s.filePath)}
+            className="flex w-full items-center gap-2 rounded px-2 py-1 text-left hover:bg-card/50"
+            data-testid="git-status-row"
+          >
+            {STATUS_ICON[s.status]}
+            <span className="w-3 font-mono text-xs">{STATUS_LABEL[s.status]}</span>
+            <span className="truncate font-mono">{s.filePath.replace(rootPath + '/', '')}</span>
+          </button>
+        ))}
+      </div>
+    </div>
+  );
+}

src/renderer/components/sidebar/Sidebar.tsx

@@ -5,6 +5,7 @@ import { ScrollArea } from '@/components/ui/scroll-area';
 import { useFileStore } from '@/stores/file-store';
 import { FileTree } from './FileTree';
 import { Outline } from './Outline';
+import { GitStatusPanel } from './GitStatusPanel';
 
 export function Sidebar() {
   const tree = useFileStore((s) => s.tree);
@@ -49,6 +50,21 @@ export function Sidebar() {
           </ScrollArea>
         </CollapsibleContent>
       </Collapsible>
+
+      {/* Git section */}
+      <Collapsible defaultOpen>
+        <CollapsibleTrigger asChild>
+          <button className="flex w-full items-center gap-1.5 px-1 py-1.5 text-xs font-medium hover:bg-accent rounded">
+            <ChevronRight size={12} className="rotate-90" />
+            Git
+          </button>
+        </CollapsibleTrigger>
+        <CollapsibleContent>
+          <ScrollArea className="h-[calc(100vh-240px)]">
+            <GitStatusPanel />
+          </ScrollArea>
+        </CollapsibleContent>
+      </Collapsible>
     </div>
   );
 }

src/renderer/lib/commands/register-menu-commands.ts

@@ -66,7 +66,7 @@ export function registerMenuCommands(): void {
       if (typeof window !== 'undefined') window.dispatchEvent(new CustomEvent('mc:print'));
     },
     'git.refresh': () => {
-      /* stub — actual refresh is a useEffect in GitStatusPanel */
+      if (typeof window !== 'undefined') window.dispatchEvent(new CustomEvent('mc:git-refresh'));
     },
   });
 

tests/component/sidebar/GitStatusPanel.test.tsx

@@ -0,0 +1,73 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { render, screen } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import { GitStatusPanel } from '@/components/sidebar/GitStatusPanel';
+import { useFileStore } from '@/stores/file-store';
+
+vi.mock('@/lib/ipc', () => ({
+  ipc: {
+    file: {
+      gitStatus: vi.fn(),
+    },
+  },
+}));
+
+import { ipc } from '@/lib/ipc';
+
+describe('GitStatusPanel', () => {
+  beforeEach(() => {
+    localStorage.clear();
+    vi.clearAllMocks();
+  });
+
+  it('shows "No folder open" when rootPath is null', () => {
+    useFileStore.setState({ rootPath: null } as any);
+    render(<GitStatusPanel />);
+    expect(screen.getByText(/no folder open/i)).toBeInTheDocument();
+  });
+
+  it('fetches and shows git status', async () => {
+    (ipc.file.gitStatus as any).mockResolvedValueOnce({
+      ok: true,
+      data: [
+        { filePath: '/project/a.md', status: 'modified' },
+        { filePath: '/project/b.md', status: 'added' },
+      ],
+    });
+    useFileStore.setState({ rootPath: '/project' } as any);
+    render(<GitStatusPanel />);
+    expect(await screen.findByText('a.md')).toBeInTheDocument();
+    expect(await screen.findByText('b.md')).toBeInTheDocument();
+  });
+
+  it('shows "Working tree clean" when no changes', async () => {
+    (ipc.file.gitStatus as any).mockResolvedValueOnce({ ok: true, data: [] });
+    useFileStore.setState({ rootPath: '/project' } as any);
+    render(<GitStatusPanel />);
+    expect(await screen.findByText(/working tree clean/i)).toBeInTheDocument();
+  });
+
+  it('shows error state when gitStatus fails', async () => {
+    (ipc.file.gitStatus as any).mockResolvedValueOnce({
+      ok: false,
+      error: { code: 'IPC_ERROR', message: 'Not a git repository' },
+    });
+    useFileStore.setState({ rootPath: '/project' } as any);
+    render(<GitStatusPanel />);
+    // The helper text appears in a <p> element distinct from the error heading
+    expect(await screen.findByText('Not a git repository, or git not installed.')).toBeInTheDocument();
+  });
+
+  it('opens file on click', async () => {
+    const openFile = vi.fn();
+    (ipc.file.gitStatus as any).mockResolvedValueOnce({
+      ok: true,
+      data: [{ filePath: '/project/a.md', status: 'modified' }],
+    });
+    useFileStore.setState({ rootPath: '/project', openFile } as any);
+    render(<GitStatusPanel />);
+    const row = await screen.findByTestId('git-status-row');
+    await userEvent.click(row);
+    expect(openFile).toHaveBeenCalledWith('/project/a.md');
+  });
+});

tests/component/sidebar/Sidebar.test.tsx

@@ -13,6 +13,7 @@ vi.mock('@/lib/ipc', () => ({
       pickFile: vi.fn(),
       read: vi.fn(),
       write: vi.fn(),
+      gitStatus: vi.fn().mockResolvedValue({ ok: true, data: [] }),
     },
   },
 }));

tests/integration/phase5-smoke.test.tsx

@@ -36,6 +36,7 @@ vi.mock('@/lib/ipc', () => ({
       pickFolder: vi.fn().mockResolvedValue({ ok: true, data: '/root' }),
       pickFile: vi.fn().mockResolvedValue({ ok: true, data: '/root/README.md' }),
       onChange: vi.fn(() => () => {}),
+      gitStatus: vi.fn().mockResolvedValue({ ok: true, data: [] }),
     },
     menu: {
       on: vi.fn(() => () => {}),
@@ -54,6 +55,8 @@ describe('Phase 5 integration', () => {
       activeTabId: null,
     });
     useEditorStore.setState({ buffers: new Map(), activeId: null });
+    // Also clear the active buffer so breadcrumb symbols won't show stale heading text
+    useEditorStore.getState().buffers.clear();
     useAppStore.setState({
       sidebarVisible: true,
       previewVisible: true,
@@ -128,12 +131,14 @@ describe('Phase 5 integration', () => {
       ],
       activeTabId: '/a.md',
     });
+    // Use a buffer content that won't conflict with tab title in breadcrumb symbols
+    useEditorStore.setState({ buffers: new Map([['/a.md', { id: '/a.md', path: '/a.md', content: '# Hello', dirty: false }], ['/b.md', { id: '/b.md', path: '/b.md', content: '# World', dirty: false }]]), activeId: '/a.md' });
     render(<AppShell />);
-    const aTab = screen.getByText('a.md').closest('[role="tab"]')!;
-    const bTab = screen.getByText('b.md').closest('[role="tab"]')!;
-    expect(aTab).toHaveAttribute('aria-current', 'page');
+    // Use role="tab" to find tabs specifically, avoiding breadcrumb "a.md" text
+    const tabs = screen.getAllByRole('tab');
+    expect(tabs[0]).toHaveAttribute('aria-current', 'page');
     await act(async () => {
-      fireEvent.click(bTab);
+      fireEvent.click(tabs[1]);
     });
     expect(useFileStore.getState().activeTabId).toBe('/b.md');
   });

tests/integration/phase6-smoke.test.tsx

@@ -35,6 +35,7 @@ vi.mock('@/lib/ipc', () => ({
       pickFolder: vi.fn().mockResolvedValue({ ok: true, data: '/root' }),
       pickFile: vi.fn().mockResolvedValue({ ok: true, data: '/root/README.md' }),
       onChange: vi.fn(() => () => {}),
+      gitStatus: vi.fn().mockResolvedValue({ ok: true, data: [] }),
     },
     menu: {
       on: vi.fn((channel: string, cb: (...args: unknown[]) => void) => {