feat: systemd unit acties via podman-helper Unix socket

start/stop/restart van systemd units gaan nu via de host-helper
(/run/podman-helper.sock) in plaats van directe systemctl subprocess
vanuit de container. Hiermee wordt de user namespace isolatie omzeild
die D-Bus calls vanuit de container onbetrouwbaar maakt.

- common.py: _helper_call(action, unit) toegevoegd
- app_system.py: /{action}/{unit} route gebruikt helper voor start/stop/restart
- app_containers.py: container_action() gebruikt helper
- daemon-reload en is-active blijven subprocess (read-only, werkt al)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

control/app_containers.py

@@ -13,6 +13,7 @@ from fastapi import APIRouter, HTTPException
 from fastapi.responses import StreamingResponse
 from pydantic import BaseModel, Field
 from common import (
+    _helper_call,
     _map_pod_to_unit,
     _podman_action_post,
     _podman_get_json,
@@ -563,7 +564,7 @@ def init_containers_router(
 
         def _systemd_call():
             if name in defined:
-                code, out = systemctl_func(["systemctl", "--user", action, name])
+                code, out = _helper_call(action, f"{name}.service")
                 _sys["code"] = code
                 _sys["out"] = out
                 if code == 0:

control/app_system.py

@@ -3,6 +3,7 @@ import subprocess
 
 from fastapi import APIRouter, HTTPException
 from common import (
+    _helper_call,
     _podman_get_json as _common_podman_get_json,
     _systemctl as _common_systemctl,
     run,
@@ -93,7 +94,10 @@ def init_system_router(session, podman_api_base: str, workloads_dir: str) -> API
         if action not in ("status", "start", "stop", "restart"):
             raise HTTPException(status_code=400, detail="Invalid action")
         cmd = ["systemctl", "--user", action, unit]
-        code, out = _run_systemctl_action(action, unit)
+        if action in ("start", "stop", "restart"):
+            code, out = _helper_call(action, unit)
+        else:
+            code, out = _run_systemctl_action(action, unit)
         return {"cmd": " ".join(cmd), "exit": code, "output": out}
 
     return router

control/common.py

@@ -1,7 +1,35 @@
+import json
+import socket
 import subprocess
 
 from fastapi import HTTPException
 
+HELPER_SOCKET = "/run/podman-helper.sock"
+
+
+def _helper_call(action: str, unit: str) -> tuple[int, str]:
+    """Stuur start/stop/restart naar de host-helper via Unix socket.
+    Returntype identiek aan run(): (returncode, output)."""
+    payload = json.dumps({"action": action, "unit": unit}).encode()
+    try:
+        with socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) as s:
+            s.settimeout(35)
+            s.connect(HELPER_SOCKET)
+            s.sendall(payload)
+            s.shutdown(socket.SHUT_WR)
+            data = b""
+            while True:
+                chunk = s.recv(4096)
+                if not chunk:
+                    break
+                data += chunk
+        resp = json.loads(data.decode())
+        if resp.get("ok"):
+            return 0, resp.get("output", "")
+        return 1, resp.get("error", "mislukt")
+    except Exception as e:
+        return 1, f"helper niet bereikbaar: {e}"
+
 
 def run(cmd):
     try: