Add MockRateLimiter test utility

Introduce tests/mock_limiter.py providing a MockRateLimiter class for tests. The mock is configurable via should_allow and an optional state, returns (allowed, state) from check(key, weight), records check calls, and supports reset() to clear recorded calls. Default state values mirror common rate-limit fields (allowed, remaining, limit, retry_after, reset_after).

Author: vladlen-codes

tests/mock_limiter.py

@@ -0,0 +1,18 @@
+class MockRateLimiter:    
+    def __init__(self, should_allow=True, state=None):
+        self.should_allow = should_allow
+        self.state = state or {
+            'allowed': should_allow,
+            'remaining': 50 if should_allow else 0,
+            'limit': 100,
+            'retry_after': 0 if should_allow else 30.0,
+            'reset_after': 60.0
+        }
+        self.check_calls = []
+    
+    def check(self, key, weight=1):
+        self.check_calls.append((key, weight))
+        return self.should_allow, self.state
+    
+    def reset(self):
+        self.check_calls = []