test: clean up concurrent cooldown processes

tests/test_community_cli.py

@@ -137,9 +137,9 @@ def test_check_and_reserve_atomic_under_concurrent_access(tmp_path: Path) -> Non
     import multiprocessing
 
     state_file = tmp_path / "concurrent.json"
-    results = multiprocessing.Manager().list()
-
-    # Launch 3 processes simultaneously
+    # Explicitly shut down the manager and never leak a timed-out child.
+    with multiprocessing.Manager() as manager:
+        results = manager.list()
         processes = []
         for i in range(3):
             args = (i, str(state_file), results)
@@ -149,6 +149,10 @@ def test_check_and_reserve_atomic_under_concurrent_access(tmp_path: Path) -> Non
             p.start()
         for p in processes:
             p.join(timeout=10)
+        for p in processes:
+            if p.is_alive():
+                p.terminate()
+                p.join(timeout=2)
 
         # At most one should succeed
         ok_count = sum(1 for _, r in results if r == "ok")