feat(uConsole): add disko, backlight fix, GPIO 23, mt7921u

- Add disko flake input + partition config (/boot/firmware, /, /home)
- Add cm5-backlight-fix service as display fallback
- Add enable-gpio23-usb-hub service for internal USB hub
- Add mt7921u kernel module for MediaTek AC1200 WiFi
- Add gpiod package for GPIO userspace control

hosts/uConsole/disko-config.nix

@@ -0,0 +1,48 @@
+{ lib, ... }:
+{
+  disk = {
+    main = {
+      type = "disk";
+      device = "/dev/disk/by-path/platform-fe340000.mmc";
+      content = {
+        type = "gpt";
+        partitions = {
+          boot = {
+            name = "FIRMWARE";
+            size = "1G";
+            type = "EF00";
+            content = {
+              type = "filesystem";
+              format = "vfat";
+              mountpoint = "/boot/firmware";
+              mountOptions = [
+                "fmask=0022"
+                "dmask=0022"
+              ];
+            };
+          };
+          root = {
+            name = "NIXOS_UCM5";
+            size = "30G";
+            content = {
+              type = "filesystem";
+              format = "ext4";
+              mountpoint = "/";
+              mountOptions = [ "noatime" ];
+            };
+          };
+          home = {
+            name = "NIXOS_HOME";
+            size = "100%";
+            content = {
+              type = "filesystem";
+              format = "ext4";
+              mountpoint = "/home";
+              mountOptions = [ "noatime" ];
+            };
+          };
+        };
+      };
+    };
+  };
+}