feat(networking): configure unused network ports to prevent errors and optimize boot time

systems/jeeves/services/systemd.nix

@@ -16,6 +16,20 @@ in
           ExecStart = "${pkgs.bash}/bin/bash ${../scripts/plex_permission.sh}";
         };
       };
+      # The unused onboard i350 port hangs ~90s after every boot ("PCIe
+      # link lost", MMIO reads return all-Fs) even with pcie_aspm=off.
+      # Remove it from the PCI bus so nothing (hwmon temperature polls,
+      # networkd) touches the dead hardware. Reversible via
+      # `echo 1 > /sys/bus/pci/rescan`.
+      remove_dead_igb_port = {
+        wantedBy = [ "multi-user.target" ];
+        description = "removes hung i350 port 0000:61:00.0 from the PCI bus";
+        unitConfig.ConditionPathExists = "/sys/bus/pci/devices/0000:61:00.0/remove";
+        serviceConfig = {
+          Type = "oneshot";
+          ExecStart = "${pkgs.bash}/bin/bash -c 'echo 1 > /sys/bus/pci/devices/0000:61:00.0/remove'";
+        };
+      };
       startup_validation = {
         requires = [ "network-online.target" ];
         after = [ "network-online.target" ];