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

lib/system_import.py

@@ -379,20 +379,26 @@ def _parse_wireguard_conf(text: str) -> dict[str, Any]:
 
 
 def import_networkd() -> bool:
-    """Parse /etc/systemd/network/99-*.network -> config/network/config.json."""
+    """Parse /etc/systemd/network/*.network -> config/network/config.json."""
     if not NETWORKD_DIR.exists():
         logger.debug("Skipping network: %s not found", NETWORKD_DIR)
         return False
 
-    network_files = sorted(NETWORKD_DIR.glob("99-*.network"))
+    network_files = sorted(NETWORKD_DIR.glob("*.network"))
     if not network_files:
-        logger.debug("Skipping network: no 99-*.network files")
+        logger.debug("Skipping network: no *.network files")
         return False
 
     parsed_interfaces: dict[str, dict[str, Any]] = {}
     for nf in network_files:
-        # Extract interface name from filename: 99-eth0.network -> eth0
-        iface_name = nf.stem[3:]  # strip "99-"
+        # Extract interface name from filename, stripping optional priority prefix:
+        # 99-eth0.network -> eth0
+        # eth0.network -> eth0
+        base = nf.stem
+        if "-" in base and base.split("-", 1)[0].isdigit():
+            iface_name = base.split("-", 1)[1]
+        else:
+            iface_name = base
         try:
             parsed_interface = _parse_network_file(nf)
             if parsed_interface: