fix: isolate _approvals_lock on agent deepcopy

asyncio.Lock deepcopy silently shares internal waiter state, so cloned
agents shared approval-lock internals with the original. Replace it with
a fresh asyncio.Lock in Agent.__deepcopy__, consistent with the existing
cache/cost lock handling, and add a regression test.

Co-authored-by: Mervin Praison <[email protected]>

src/praisonai-agents/praisonaiagents/agent/agent.py

@@ -2457,7 +2457,8 @@ Your Goal: {self.goal}
         """Custom deepcopy that creates fresh threading primitives.
 
         threading primitives cannot be deep-copied on all supported Python
-        versions. This hook replaces the Agent-owned locks directly, while
+        versions, and ``asyncio.Lock`` copies silently share internal waiter
+        state. This hook replaces the Agent-owned locks directly, while
         lock-bearing state wrappers provide their own deepcopy hooks, so the
         clone receives independent state and fresh locks.
         """
@@ -2470,6 +2471,8 @@ Your Goal: {self.goal}
                 object.__setattr__(result, k, threading.RLock())
             elif k == "_cost_lock":
                 object.__setattr__(result, k, threading.Lock())
+            elif k == "_approvals_lock":
+                object.__setattr__(result, k, asyncio.Lock())
             else:
                 object.__setattr__(result, k, copy.deepcopy(v, memo))
         return result

src/praisonai-agents/tests/unit/agent/test_agent_clone.py

@@ -94,3 +94,13 @@ class TestAgentDeepCopy:
         assert cloned._Agent__chat_history_state is not agent._Agent__chat_history_state
         assert cloned._Agent__snapshot_state is not agent._Agent__snapshot_state
         assert cloned._turn_tools_lock is not agent._turn_tools_lock
+
+    def test_deepcopy_isolates_approvals_lock(self):
+        import asyncio
+
+        agent = self._make_agent()
+        cloned = copy.deepcopy(agent)
+
+        assert cloned._approvals_lock is not agent._approvals_lock
+        assert isinstance(cloned._approvals_lock, asyncio.Lock)
+        assert cloned._pending_approvals is not agent._pending_approvals