feat: send welcome emails through smtp

package.json

@@ -23,6 +23,7 @@
     "fastify": "^5.3.2",
     "fastify-plugin": "^5.0.1",
     "lucide-react": "0.344.0",
+    "nodemailer": "^10.0.1",
     "pg": "^8.16.3",
     "react": "18.2.0",
     "react-dom": "18.2.0",
@@ -31,6 +32,7 @@
   },
   "devDependencies": {
     "@types/node": "^22.14.0",
+    "@types/nodemailer": "^8.0.1",
     "@types/pg": "^8.15.4",
     "@vitejs/plugin-react": "^5.0.0",
     "tsx": "^4.19.4",