tests: fix mypy type errors in security tests

tests/security/pentest_session.py

@@ -9,6 +9,7 @@ import time
 import urllib.error
 import urllib.request
 from concurrent.futures import ThreadPoolExecutor, as_completed
+from typing import Any
 
 BASE_URL = "http://127.0.0.1:5099"
 
@@ -65,9 +66,9 @@ def random_content(size=1024):
     return os.urandom(size)
 
 
-def run_tests():
+def run_tests() -> dict[str, Any]:
     """Run comprehensive pentest suite."""
-    results = {"passed": 0, "failed": 0, "tests": []}
+    results: dict[str, Any] = {"passed": 0, "failed": 0, "tests": []}
     paste_ids = []
 
     def log_test(name, passed, details=""):