fix: replace incorrect patch usage with sys.modules patching in realtime tests

- Replace patch('praisonaiui.features.realtime.openai') with patch.dict(sys.modules, {'openai': ...})
- Fixes 3 failing tests: test_session_lifecycle_without_openai, test_session_lifecycle_with_mocked_openai, test_health_with_openai
- Preserves lazy-import invariant by not adding module-level openai import

Co-authored-by: Mervin Praison <MervinPraison@users.noreply.github.com>

Author: github-actions[bot]

tests/unit/test_realtime.py

@@ -78,20 +78,20 @@ class TestSessionLifecycle:
     @pytest.mark.asyncio
     async def test_session_lifecycle_without_openai(self):
         """Test session lifecycle when OpenAI SDK not available."""
+        import sys
         manager = OpenAIRealtimeManager()
 
-        # Mock ImportError for openai package
-        with patch('praisonaiui.features.realtime.openai', None):
-            # Mock import to raise ImportError
-            with patch('builtins.__import__', side_effect=ImportError("No module named 'openai'")):
-                session_info = await manager.create_session()
-                
-                assert session_info["type"] == "error"
-                assert "openai package not installed" in session_info["error"]
+        # Force `import openai` inside the function body to fail
+        with patch.dict(sys.modules, {"openai": None}):
+            session_info = await manager.create_session()
+            
+            assert session_info["type"] == "error"
+            assert "openai package not installed" in session_info["error"]
 
     @pytest.mark.asyncio
     async def test_session_lifecycle_with_mocked_openai(self):
         """Test full session lifecycle with mocked OpenAI."""
+        import sys
         manager = OpenAIRealtimeManager()
 
         # Mock OpenAI client and response
@@ -103,7 +103,7 @@ async def test_session_lifecycle_with_mocked_openai(self):
         mock_client.realtime.sessions.create = AsyncMock(return_value=mock_response)
         mock_openai.OpenAI.return_value = mock_client
 
-        with patch('praisonaiui.features.realtime.openai', mock_openai):
+        with patch.dict(sys.modules, {"openai": mock_openai}):
             # Create session
             session_info = await manager.create_session(model="gpt-4o-realtime-preview")
 
@@ -170,14 +170,15 @@ def test_health_without_openai(self):
 
     def test_health_with_openai(self):
         """Test health when OpenAI is available."""
+        import sys
         manager = OpenAIRealtimeManager()
 
         # Add some sessions to test counter
         manager._sessions["session_1"] = {"id": "session_1"}
         manager._sessions["session_2"] = {"id": "session_2"}
 
         mock_openai = mock.MagicMock()
-        with patch('praisonaiui.features.realtime.openai', mock_openai):
+        with patch.dict(sys.modules, {"openai": mock_openai}):
             health = manager.health()
 
             assert health["status"] == "ok"