fix: add missing __init__.py to tests/api subpackages to fix relative imports

tests/api/fleet/test_get_deckies.py

@@ -0,0 +1,16 @@
+from fastapi.testclient import TestClient
+from decnet.web.api import app
+from decnet.env import DECNET_ADMIN_USER, DECNET_ADMIN_PASSWORD
+
+def test_get_deckies_endpoint(mock_state_file):
+    with TestClient(app) as _client:
+        # Login to get token
+        _login_resp = _client.post("/api/v1/auth/login", json={"username": DECNET_ADMIN_USER, "password": DECNET_ADMIN_PASSWORD})
+        _token = _login_resp.json()["access_token"]
+        
+        _response = _client.get("/api/v1/deckies", headers={"Authorization": f"Bearer {_token}"})
+        assert _response.status_code == 200
+        _data = _response.json()
+        assert len(_data) == 2
+        assert _data[0]["name"] == "test-decky-1"
+        assert _data[0]["service_config"]["ssh"]["banner"] == "SSH-2.0-OpenSSH_8.9"