add nix-on-droid epral config

droid/default.nix

@@ -0,0 +1,6 @@
+{ inputs, ... }@flakeContext:
+{
+  nixOnDroidConfigurations = {
+    epral = import ./epral.nix flakeContext; # epral (Android via nix-on-droid)
+  };
+}

droid/epral.nix

@@ -0,0 +1,66 @@
+{ inputs, ... }@flakeContext:
+let
+  # Host: epral (Android device via nix-on-droid, aarch64-linux)
+  # NOTE: nix-on-droid uses its own module system (class = "nixOnDroid").
+  # Only options defined by nix-on-droid are available here:
+  #   environment.*, nix.*, time.*, networking.hosts, user.*, home-manager.*, system.stateVersion
+  # NixOS-only options (boot.*, services.*, hardware.*, fileSystems.*, ...) do NOT exist here.
+  nixOnDroidModule =
+    {
+      config,
+      lib,
+      pkgs,
+      ...
+    }:
+    {
+      # user.home is read-only and always /data/data/com.termux.nix/files/home
+      user.userName = "oqyude"; # matches xlib.device.username used by the NixOS hosts
+
+      environment = {
+        # Base CLI packages
+        packages = with pkgs; [
+          vim
+          git
+          ripgrep
+          htop
+          file
+          tmux
+        ];
+        # Backup existing files in /etc instead of failing activation
+        etcBackupExtension = ".bak";
+      };
+
+      # Set up nix for flakes
+      nix.extraOptions = ''
+        experimental-features = nix-command flakes
+      '';
+
+      time.timeZone = "Europe/Moscow";
+
+      # Read the changelog before changing this value.
+      # nix-on-droid currently supports state versions only up to "24.05".
+      system.stateVersion = "24.05";
+
+      # home-manager is built in; point it at this repo's home-manager input
+      # and keep the config self-contained (repo home.nix depends on NixOS-only xlib.dirs).
+      # home-manager = {
+      #   backupFileExtension = "hm-bak";
+      #   useGlobalPkgs = true;
+      #   config = { config, lib, pkgs, ... }: {
+      #     home.stateVersion = "24.05";
+      #     home.packages = with pkgs; [ ];
+      #   };
+      # };
+    };
+in
+inputs.nix-on-droid.lib.nixOnDroidConfiguration {
+  pkgs = import inputs.nixpkgs {
+    system = "aarch64-linux";
+  };
+  modules = [
+    nixOnDroidModule
+  ];
+  extraSpecialArgs = {
+    inherit inputs;
+  };
+}

flake.nix

@@ -24,6 +24,10 @@
         nixpkgs.follows = "nixpkgs";
       };
     };
+    nix-on-droid = {
+      url = "github:nix-community/nix-on-droid/master";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
     deploy-rs = {
       url = "github:serokell/deploy-rs";
       inputs = {
@@ -113,6 +117,7 @@
     }
     // (import ./configurations flakeContext)
     // (import ./deploy flakeContext)
+    // (import ./droid flakeContext)
     // (import ./home flakeContext)
     // (import ./modules flakeContext)
     // (import ./overlays flakeContext)