fix(ci): generate HMAC key for test_smoke.py in CI

- test_smoke.py loads the real policy which needs ./keys/mcp_hmac_key
- Add key generation step before running tests

Author: ovitrac

.github/workflows/publish.yml

@@ -29,6 +29,9 @@ jobs:
       - name: Install cloakmcp with test extras
         run: pip install -e ".[test]"
 
+      - name: Generate test HMAC key
+        run: mkdir -p keys && openssl rand -hex 32 > keys/mcp_hmac_key
+
       - name: Run tests (including slow)
         run: pytest tests/ -v -m ""