Fix: voorkom pods uit .container workloads

/api/pods-dashboard genereerde onterecht 'pod<basename>' entries voor .container Quadlet-bestanden, wat leidde tot lege nep-pods zoals 'podn8n' in de WebUI.

Alleen echte pod-workloads (.pod, evt. .kube) mogen nog een Source:"systemd" pod-row opleveren.

Geen endpoint- of schemawijzigingen. Alleen filtering in control/app_pods.py aangepast.

control/app_pods.py

@@ -36,9 +36,11 @@ def init_pods_router(
 
     def _append_defined_pods_dashboard_rows(dashboard: list, by_name: dict, root_dir: str):
         # preserves original os.walk order and file iteration order
+        SUPPORTED_POD_WORKLOAD_EXTENSIONS = {".pod", ".kube"}
         for root, _, files in os.walk(root_dir):
             for f in files:
-                if f.endswith((".yaml", ".yml")):
+                _, ext = os.path.splitext(f)
+                if ext in SUPPORTED_POD_WORKLOAD_EXTENSIONS:
                     base = os.path.splitext(os.path.basename(f))[0]
                     pod_name = f"pod{base}"
                     unit_name = _map_pod_to_unit(pod_name)