refactor: fit structure of main directories

devShells/flake/default.nix

@@ -0,0 +1,46 @@
+{
+  mkShell,
+  writeShellApplication,
+  # deps
+  findutils,
+  gnused,
+  nix-output-monitor,
+  ...
+}:
+mkShell {
+  packages = [
+    (writeShellApplication {
+      name = "mkIso";
+
+      runtimeInputs = [
+        nix-output-monitor
+      ];
+
+      text = ''
+        isoConfig="nixosConfigurations.live-image.config.system.build.isoImage"
+        nom build "$FLAKE#$isoConfig"
+      '';
+    })
+
+    (writeShellApplication {
+      name = "fixUidChange";
+
+      runtimeInputs = [
+        findutils
+        gnused
+      ];
+
+      text = ''
+        GROUP="$1"
+        OLD_GID="$2"
+        NEW_GID="$3"
+
+        # Remove generated group entry
+        sudo sed -i -e "/^$GROUP:/d" /etc/group
+
+        # Change GID on existing files
+        sudo find / -gid "$OLD_GID" -exec chgrp "$NEW_GID" {} +
+      '';
+    })
+  ];
+}