feat(backend): add collection region staff CRUD and list summaries

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

backend/tests/test_collection_region_staff_helpers.py

@@ -0,0 +1,26 @@
+import unittest
+
+from app.crud.collection_region import staff_display_name, build_staff_leader_name_lists
+
+
+class CollectionRegionStaffHelperTests(unittest.TestCase):
+    def test_staff_display_name_prefers_nick_name(self):
+        self.assertEqual(staff_display_name("张敏", "SQ001"), "张敏")
+
+    def test_staff_display_name_falls_back_to_user_no(self):
+        self.assertEqual(staff_display_name("", "SQ001"), "SQ001")
+        self.assertEqual(staff_display_name(None, "SQ001"), "SQ001")
+
+    def test_build_staff_leader_name_lists_leaders_first_in_staff(self):
+        rows = [
+            {"userId": "u2", "nickName": "李强", "isLeader": False},
+            {"userId": "u1", "nickName": "张敏", "isLeader": True},
+            {"userId": "u3", "nickName": "王芳", "isLeader": True},
+        ]
+        staff_names, leader_names = build_staff_leader_name_lists(rows)
+        self.assertEqual(leader_names, ["张敏", "王芳"])
+        self.assertEqual(staff_names, ["张敏", "王芳", "李强"])
+
+
+if __name__ == "__main__":
+    unittest.main()