Add EmailJS integration for free email sending

- Install @emailjs/browser for client-side email
- Update prayer submission to send immediate emails via EmailJS
- Add EmailJS configuration to environment variables
- Update README with EmailJS setup instructions
- Keep server-side scheduled emails for cron jobs

package.json

@@ -10,6 +10,7 @@
   },
   "dependencies": {
     "@dataconnect/generated": "file:src/dataconnect-generated",
+    "@emailjs/browser": "^4.4.1",
     "firebase": "^12.4.0",
     "next": "16.0.0",
     "next-pwa": "^5.6.0",