chore(ci): add EMAIL_FROM to staging deploy config

Pass the staging email sender address to the container.

Author: zainfathoni

config/deploy.staging.yml

@@ -40,6 +40,7 @@ env:
     PORT: "3000"
     DATABASE_URL: file:/app/prisma/staging.db
     STAGING_ENVIRONMENT: "true"
+    EMAIL_FROM: Rumah Berbagi Staging <staging@rumahberbagi.com>
   # Secret environment variables (loaded from .kamal/secrets)
   secret:
     - SESSION_SECRET