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/handlers/system.py

@@ -0,0 +1,35 @@
+"""System metrics handler.
+
+Returns CPU load, memory usage, and per-interface network traffic stats.
+"""
+
+from __future__ import annotations
+
+import logging
+from typing import Any
+
+from daemon.iface import GET_SYSTEM_METRICS
+from daemon.server import registry
+from lib.state import state as state_store
+
+logger = logging.getLogger(__name__)
+
+
+@registry.register(GET_SYSTEM_METRICS)
+def system_metrics(_request: Any, _body: Any) -> dict[str, Any]:
+    """Return system-wide metrics.
+
+    Reads from pre-collected state (CPU load, memory, network traffic).
+
+    Returns:
+        Dict with load, memory, swap, and traffic data.
+    """
+    sys_state = state_store.get("system")
+    if sys_state is None:
+        return {
+            "load": {"load1": 0.0, "load5": 0.0, "load15": 0.0},
+            "memory": {"total": 0, "available": 0, "used": 0, "used_pct": 0},
+            "swap": {"total": 0, "used": 0, "used_pct": 0},
+            "traffic": {},
+        }
+    return sys_state

daemon/iface.py

@@ -155,12 +155,12 @@ GET_LOGS_APP: Endpoint = _ep("GET", "/logs/app")
 
 # ---- Server infra (not going through client) ----
 GET_HEALTH: Endpoint = _ep("GET", "/health")
-GET_STATUS_ALL: Endpoint = _ep("GET", "/status/all")
 POST_STATUS_REFRESH: Endpoint = _ep("POST", "/status/refresh")
 GET_WS: Endpoint = _ep("GET", "/ws")
 POST_BATCH: Endpoint = _ep("POST", "/batch")
 GET_STATUS_PENDING: Endpoint = _ep("GET", "/status/pending")
 POST_STATUS_APPLY_ALL: Endpoint = _ep("POST", "/status/apply-all")
+GET_SYSTEM_METRICS: Endpoint = _ep("GET", "/system/metrics")
 
 # Collect all endpoint module-level constants for __all__ verification
 _all_endpoints = [

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
     )