fix(core): resolve build and lint failures in worktreeService

- Fix incorrect 'fs.promises' usage
- Provide missing 'projectRoot' to 'isGeminiWorktree'
- Replace 'any' with specific types and type guards to satisfy ESLint
- Update tests to match implementation changes

packages/core/src/services/worktreeService.test.ts

@@ -86,7 +86,7 @@ describe('worktree utilities', () => {
 
   describe('createWorktree', () => {
     it('should execute git worktree add with correct branch and path if it does not exist', async () => {
-      vi.mocked(fs.promises.stat).mockRejectedValue({ code: 'ENOENT' } as any);
+      vi.mocked(fs.stat).mockRejectedValue({ code: 'ENOENT' });
       vi.mocked(execa).mockResolvedValue({ stdout: '' } as never);
 
       const resultPath = await createWorktree(projectRoot, worktreeName);
@@ -100,7 +100,9 @@ describe('worktree utilities', () => {
     });
 
     it('should return existing path and not call git if it already exists', async () => {
-      vi.mocked(fs.promises.stat).mockResolvedValue({ isDirectory: () => true } as any);
+      vi.mocked(fs.stat).mockResolvedValue({
+        isDirectory: () => true,
+      } as never);
 
       const resultPath = await createWorktree(projectRoot, worktreeName);
 
@@ -109,7 +111,7 @@ describe('worktree utilities', () => {
     });
 
     it('should throw an error if git worktree add fails', async () => {
-      vi.mocked(fs.promises.stat).mockRejectedValue({ code: 'ENOENT' } as any);
+      vi.mocked(fs.stat).mockRejectedValue({ code: 'ENOENT' });
       vi.mocked(execa).mockRejectedValue(new Error('git failed'));
 
       await expect(createWorktree(projectRoot, worktreeName)).rejects.toThrow(

packages/core/src/services/worktreeService.ts

@@ -128,12 +128,19 @@ export async function createWorktree(
   }
 
   try {
-    const stats = await fs.promises.stat(worktreePath);
-    if (stats.isDirectory() && await isGeminiWorktree(worktreePath)) {
+    const stats = await fs.stat(worktreePath);
+    if (stats.isDirectory() && isGeminiWorktree(worktreePath, projectRoot)) {
       return worktreePath;
     }
-  } catch (err) {
-    if (err.code !== 'ENOENT') throw err;
+  } catch (err: unknown) {
+    if (
+      err &&
+      typeof err === 'object' &&
+      'code' in err &&
+      err.code !== 'ENOENT'
+    ) {
+      throw err;
+    }
   }
 
   const branchName = `worktree-${name}`;