Add VK callback auth support and admin demotion

tests/test_main_contracts.py

@@ -27,7 +27,7 @@ class MainContractsTests(unittest.TestCase):
         return ast.walk(node)
 
     def test_auth_error_contexts_contains_only_supported_contexts(self):
-        expected_contexts = {"load_chats", "execute_user_action", "set_user_admin"}
+        expected_contexts = {"load_chats", "execute_user_action", "set_user_admin", "unset_user_admin"}
         for node in self.module.body:
             if isinstance(node, ast.Assign):
                 for target in node.targets:
@@ -37,6 +37,52 @@ class MainContractsTests(unittest.TestCase):
                         return
         self.fail("AUTH_ERROR_CONTEXTS assignment not found")
 
+    def test_unset_user_admin_method_exists(self):
+        self._find_method("unset_user_admin")
+
+    def test_uses_custom_standalone_vk_app(self):
+        constants = {}
+        for node in self.module.body:
+            if not isinstance(node, ast.Assign) or len(node.targets) != 1:
+                continue
+            target = node.targets[0]
+            if isinstance(target, ast.Name):
+                try:
+                    constants[target.id] = ast.literal_eval(node.value)
+                except Exception:
+                    continue
+
+        self.assertEqual(constants.get("VK_APP_ID"), "54454043")
+        self.assertIn("ANABASIS_VK_REDIRECT_URI", self.main_source)
+        self.assertIn("https://vk.daemonlord.ru/vk/callback", self.main_source)
+
+    def test_remove_action_demotes_member_before_removing(self):
+        bulk_worker = None
+        for node in self.module.body:
+            if isinstance(node, ast.ClassDef) and node.name == "BulkActionWorker":
+                bulk_worker = node
+                break
+        self.assertIsNotNone(bulk_worker, "BulkActionWorker class not found")
+
+        run_method = None
+        for node in bulk_worker.body:
+            if isinstance(node, ast.FunctionDef) and node.name == "run":
+                run_method = node
+                break
+        self.assertIsNotNone(run_method, "BulkActionWorker.run method not found")
+
+        has_member_role = False
+        has_remove_call = False
+        for node in ast.walk(run_method):
+            if isinstance(node, ast.keyword) and node.arg == "role":
+                if isinstance(node.value, ast.Constant) and node.value.value == "member":
+                    has_member_role = True
+            if isinstance(node, ast.Attribute) and node.attr == "removeChatUser":
+                has_remove_call = True
+
+        self.assertTrue(has_member_role, "remove action must demote admins with role='member'")
+        self.assertTrue(has_remove_call, "remove action must still call removeChatUser")
+
     def test_check_for_updates_has_reentry_guard(self):
         method = self._find_method("check_for_updates")
         has_guard = False