add 500k memory leak tests for comprehensive analysis

- Add test_memory_baseline_500k for router (500,000 requests)
- Add test_proxy_memory_baseline_500k for proxy (500,000 requests)
- These high-volume tests are designed for manual execution and deep memory leak analysis
- Not included in CI due to long runtime (~15-30 minutes each)
- Useful for detecting very gradual memory accumulation patterns
- Run individually with: pytest tests/load_tests/test_*_memory_growth.py::test_*_500k -v

tests/load_tests/test_proxy_chat_completions_memory_growth.py

@@ -439,3 +439,20 @@ async def test_proxy_memory_baseline_50k(proxy_server, limit_memory):
         pytest tests/load_tests/test_proxy_chat_completions_memory_growth.py::test_proxy_memory_baseline_50k -v
     """
     await run_proxy_memory_baseline_test(50000, proxy_server, limit_memory)
+
+@pytest.mark.asyncio
+@pytest.mark.limit_leaks(MEMORY_LIMIT)
+@pytest.mark.no_parallel  # Must run sequentially - measures process memory
+async def test_proxy_memory_baseline_500k(proxy_server, limit_memory):
+    """
+    Memory baseline test with 500,000 requests to the proxy server.
+    Uses @pytest.mark.limit_leaks("40 MB") to enforce memory limit.
+    If test_proxy_memory_baseline_1k and test_proxy_memory_baseline_2k pass but this fails,
+    it's a clear sign of sequential/progressive memory growth.
+    
+    NOTE: This test should be run INDIVIDUALLY, not with other tests in this file.
+    Running multiple tests together causes memory baseline drift, making it difficult
+    to accurately detect linear memory growth. Run with:
+        pytest tests/load_tests/test_proxy_chat_completions_memory_growth.py::test_proxy_memory_baseline_500k -v
+    """
+    await run_proxy_memory_baseline_test(500000, proxy_server, limit_memory)

tests/load_tests/test_router_acompletion_memory_growth.py

@@ -138,3 +138,20 @@ async def test_memory_baseline_50k(test_router, limit_memory):
         pytest tests/load_tests/test_router_acompletion_memory_growth.py::test_memory_baseline_50k -v
     """
     await run_memory_baseline_test(50000, test_router, limit_memory)
+
+@pytest.mark.asyncio
+@pytest.mark.limit_leaks(MEMORY_LIMIT)
+@pytest.mark.no_parallel  # Must run sequentially - measures process memory
+async def test_memory_baseline_500k(test_router, limit_memory):
+    """
+    Memory baseline test with 500,000 requests.
+    Uses @pytest.mark.limit_leaks("40 MB") to enforce memory limit.
+    If test_memory_baseline_1k and test_memory_baseline_2k pass but this fails,
+    it's a clear sign of sequential/progressive memory growth.
+    
+    NOTE: This test should be run INDIVIDUALLY, not with other tests in this file.
+    Running multiple tests together causes memory baseline drift, making it difficult
+    to accurately detect linear memory growth. Run with:
+        pytest tests/load_tests/test_router_acompletion_memory_growth.py::test_memory_baseline_500k -v
+    """
+    await run_memory_baseline_test(500000, test_router, limit_memory)