feat: add system metrics dashboard with resource monitoring

- Add system metrics endpoint (CPU load, memory, swap, network traffic)
- Collect metrics from /proc and /sys (no subprocess required)
- Overhaul dashboard to pull from per-subsystem models
- Remove deprecated /status/all monolithic endpoint
- Improve networkd import to handle optional priority prefix
- Fix CSS duplicate .grid-4 rule and unused dashboard imports

daemon/server.py

@@ -350,7 +350,6 @@ def create_app() -> web.Application:
     """
     app = web.Application()
     app.router.add_route("GET", "/health", _health)
-    app.router.add_route("GET", "/status/all", get_status_all)
     app.router.add_route("POST", "/status/refresh", refresh_status)
     app.router.add_route("POST", "/batch", _handle_batch)
     app.router.add_route("GET", "/ws", _handle_ws)
@@ -462,15 +461,6 @@ async def _health(_request: web.Request) -> web.Response:
     return ok({"pid": os.getpid(), "socket": str(SOCKET_PATH)})
 
 
-async def get_status_all(_request: web.Request) -> web.Response:
-    """Return the entire state snapshot in one call.
-
-    Returns:
-        JSON response containing state data for all subsystems.
-    """
-    return ok({name: state_store.get(name) for name in state_store.SUBSYSTEMS})
-
-
 async def refresh_status(_request: web.Request) -> web.Response:
     """Re-collect all state from system.
 
@@ -517,6 +507,7 @@ def _register_routes() -> None:
         network,  # noqa: F401
         nginx,  # noqa: F401
         status,  # noqa: F401
+        system,  # noqa: F401
         wireguard,  # noqa: F401
     )