chore(machine): remove unused express dependency

express is only used in Lightning.Pub's withdraw extension for LNURL
HTTP endpoints, not in the ATM Electron/Vue app.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/machine/package.json

@@ -30,7 +30,6 @@
     "@vueuse/core": "^14.1.0",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
-    "express": "^5.2.1",
     "lucide-vue-next": "^0.563.0",
     "pinia": "^2.2.0",
     "qrcode.vue": "^3.6.0",
@@ -41,7 +40,6 @@
   },
   "devDependencies": {
     "@tailwindcss/vite": "^4.0.0",
-    "@types/express": "^5.0.6",
     "@types/node": "^22.0.0",
     "@vitejs/plugin-vue": "^5.2.0",
     "concurrently": "^9.0.0",