fix(mindspace): sync nested OA files and count workspace assets

Recursive workspace sync now imports files in oa/private/public subfolders,
references workspace paths without duplicating storage, and includes
workspace-sourced assets in category itemCount. Refresh counts when leaving
a category view.

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

mindspace.test.mjs

@@ -106,6 +106,7 @@ test('getSpace scopes space and categories to the authenticated user', async ()
   assert.equal(space.categories[0].code, 'private');
   assert.deepEqual(calls[0].params, ['user-1']);
   assert.deepEqual(calls[1].params, ['user-1', 'space-1']);
+  assert.doesNotMatch(calls[1].sql, /source_type\s*=\s*'upload'/);
 });
 
 test('getSpace includes schedule snapshot when schedule service is available', async () => {