fix(export): не падать с EPERM при сохранении в корень диска на Windows

Перед записью zip больше не вызываем mkdir для E:\ / C:\ — на Windows это даёт operation not permitted.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/main/project/zipStore.legacyContract.test.ts

@@ -139,6 +139,16 @@ void test('main index: full zip import loads app-tokens like playlists', () => {
   assert.match(importFromPath[0], /importAppTokensFromOpenProjectCache/);
 });
 
+void test('zipStore: zipDir uses ensureParentDir (no mkdir of drive root)', () => {
+  const src = fs.readFileSync(path.join(here, 'zipStore.ts'), 'utf8');
+  assert.match(src, /from '\.\/ensureParentDir'/);
+  const i = src.indexOf('async function zipDir(');
+  assert.ok(i >= 0);
+  const block = src.slice(i, i + 800);
+  assert.match(block, /await ensureParentDir\(outZipPath\)/);
+  assert.doesNotMatch(block, /fs\.mkdir\(path\.dirname\(outZipPath\)/);
+});
+
 void test('atomicReplace: replaceFileAtomic must not rm destination before successful commit', () => {
   const src = fs.readFileSync(path.join(here, 'atomicReplace.ts'), 'utf8');
   const i = src.indexOf('export async function replaceFileAtomic');