fix: verwijder dode Flask-stijl legacy route in app_system.py

De route @router.post("/api/<action>/<unit>") gebruikte Flask-syntaxis
die nooit matcht in FastAPI. Dead code verwijderd.

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

control/app_system.py

@@ -95,15 +95,6 @@ def init_system_router(session, podman_api_base: str, workloads_dir: str) -> API
         except Exception as e:
             raise HTTPException(status_code=500, detail=str(e))
 
-    @router.post("/api/<action>/<unit>")
-    def legacy_api_action(action: str, unit: str):
-        # legacy flask-like path; keep behavior (even if not used by index.html)
-        if action not in ("status", "start", "stop", "restart"):
-            return {"error": "Invalid action"}, 400
-        cmd = ["systemctl", "--user", action, unit]
-        code, out = _run_systemctl_action(action, unit)
-        return {"cmd": " ".join(cmd), "exit": code, "output": out}
-
     @router.post("/{action}/{unit}")
     def api_action(action: str, unit: str):
         if action not in ("status", "start", "stop", "restart"):