fix: word the cases-folder refusal for Clone Repo too (release review)

Clone Repo's picker now offers New folder, and with the field empty Browse
opens in the cases folder, so the first press there lands on this refusal.
It pointed at Add Case > Create New, which cannot clone. The sentence has to
read right from every picker that offers the button, so it names both tabs.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

test/routes/filesystem-mkdir-routes.test.ts

@@ -52,7 +52,8 @@ describe('POST /api/filesystem/mkdir', () => {
       const res = await mkdir({ path: casesDir, name: 'myproj' });
       expect(res.statusCode).toBe(400);
       expect(res.json().error).toContain('Pick a folder outside it');
-      expect(res.json().error).toContain('Add Case > Create New (no custom folder)');
+      // Every picker offering New folder sees this, and Clone Repo opens here by default.
+      expect(res.json().error).toContain('Add Case > Create New or Clone Repo (no custom folder)');
       expect(existsSync(join(casesDir, 'myproj'))).toBe(false);
       // A folder inside a case is fine.
       mkdirSync(join(casesDir, 'real-case'));