feat: nb add epicenter-vm

hosts/nb/modules/epicenter.nix

@@ -1,5 +1,45 @@
-{ lib, pkgs, ... }: 
+{ lib, pkgs, ... }:
 let
+  epicenter-vm = pkgs.writeShellScriptBin "epicenter-vm" ''
+    set -euo pipefail
+
+    VM_DIR="$HOME/epicenter-vm"
+    DISK="$VM_DIR/disk.qcow2"
+    ISO=""
+
+    while [[ $# -gt 0 ]]; do
+      case "$1" in
+        --iso) ISO="$2"; shift 2 ;;
+        *) echo "Usage: epicenter-vm [--iso /path/to/file.iso]"; exit 1 ;;
+      esac
+    done
+
+    # Create disk if it doesn't exist
+    if [ ! -f "$DISK" ]; then
+      mkdir -p "$VM_DIR"
+      ${pkgs.qemu}/bin/qemu-img create -f qcow2 "$DISK" 60G
+    fi
+
+    QEMU_ARGS=(
+      -enable-kvm
+      -m 4G
+      -smp 2
+      -drive "file=$DISK,format=qcow2,if=virtio"
+      -bios ${pkgs.OVMF.fd}/FV/OVMF.fd
+      -display gtk,gl=on
+      -device virtio-vga-gl
+      -device virtio-net-pci,netdev=net0
+      -netdev user,id=net0,hostfwd=tcp::2222-:22
+    )
+
+    # Attach ISO if provided
+    if [ -n "$ISO" ]; then
+      QEMU_ARGS+=(-cdrom "$ISO" -boot d)
+    fi
+
+    exec ${pkgs.qemu}/bin/qemu-system-x86_64 "''${QEMU_ARGS[@]}"
+  '';
+
   wrapperScript = pkgs.writeShellScriptBin "rustdesk-epicenter-wrapper" ''
     # Grant epicenter user access to the Wayland socket
     ${pkgs.acl}/bin/setfacl -m u:epicenter:x "$XDG_RUNTIME_DIR"
@@ -22,6 +62,7 @@ let
   };
 in {
   environment.systemPackages = [
+    epicenter-vm
     rustdeskEpicenterDesktopItem
   ];