fix(git): git-status IPC returns a flat array, not wrapped object

GitOperations.getStatus returns { files: [...] } but the renderer's
ipc.file.gitStatus type declares Array<...> and calls result.data.map().
The mismatch made GitStatusPanel.tsx throw 'n.map is not a function'
on mount, which blanked the entire React tree.

Unwrap result.files in the IPC handler so it returns the array the
renderer expects. Add tests covering the success, empty, and non-git
branches so this regression cannot recur.

Refs: blank-screen-on-md-open

tests/unit/main/files/git-handler.test.js

@@ -0,0 +1,72 @@
+/**
+ * Regression: src/main/files/git.js must return a flat array from the
+ * 'git-status' handler so that the renderer's `result.data.map(...)` works.
+ * Previously the handler returned `{ files: [...] }` and the renderer blew
+ * up with `n.map is not a function`, blanking the entire UI.
+ */
+const EventEmitter = require('events');
+
+class FakeIpcMain extends EventEmitter {
+  constructor() {
+    super();
+    this.handlers = new Map();
+  }
+  handle(channel, handler) {
+    this.handlers.set(channel, handler);
+  }
+}
+
+describe('files/git IPC handler', () => {
+  let ipc;
+  let register;
+  let currentFileRef;
+
+  beforeEach(() => {
+    jest.resetModules();
+    ipc = new FakeIpcMain();
+    currentFileRef = { current: null };
+    jest.doMock('electron', () => ({ ipcMain: ipc }));
+    jest.doMock('../../../../src/main/GitOperations', () => ({
+      getStatus: () => ({ files: [{ filePath: 'a.md', status: 'modified' }] }),
+    }));
+    ({ register } = require('../../../../src/main/files/git'));
+  });
+
+  test('git-status returns a flat array, not a wrapped object', async () => {
+    register(currentFileRef);
+    const handler = ipc.handlers.get('git-status');
+    const result = await handler({}, '/repo');
+    expect(Array.isArray(result)).toBe(true);
+    expect(result).toEqual([{ filePath: 'a.md', status: 'modified' }]);
+  });
+
+  test('git-status falls back to [] when GitOperations returns no files', async () => {
+    jest.resetModules();
+    ipc = new FakeIpcMain();
+    jest.doMock('electron', () => ({ ipcMain: ipc }));
+    jest.doMock('../../../../src/main/GitOperations', () => ({
+      getStatus: () => ({ files: undefined }),
+    }));
+    ({ register } = require('../../../../src/main/files/git'));
+    register(currentFileRef);
+    const handler = ipc.handlers.get('git-status');
+    const result = await handler({}, '/repo');
+    expect(Array.isArray(result)).toBe(true);
+    expect(result).toEqual([]);
+  });
+
+  test('git-status returns [] for non-git directories (error path)', async () => {
+    jest.resetModules();
+    ipc = new FakeIpcMain();
+    jest.doMock('electron', () => ({ ipcMain: ipc }));
+    jest.doMock('../../../../src/main/GitOperations', () => ({
+      getStatus: () => ({ files: [], error: 'Not a git repository' }),
+    }));
+    ({ register } = require('../../../../src/main/files/git'));
+    register(currentFileRef);
+    const handler = ipc.handlers.get('git-status');
+    const result = await handler({}, '/repo');
+    expect(Array.isArray(result)).toBe(true);
+    expect(result).toEqual([]);
+  });
+});