Fix server dependency: replace @sendgrid/mail with nodemailer

The Docker runtime stage installs from server/package.json, not the
root package.json, so the earlier SMTP migration left the deployed
image still missing nodemailer (MODULE_NOT_FOUND at boot).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: akariv

package.json

@@ -29,7 +29,6 @@
     "core-js": "^2.6.1",
     "d3": "^5.9.2",
     "d3-simple-slider": "^1.5.4",
-    "nodemailer": "^6.9.13",
     "ngx-auto-unsubscribe": "^2.4.1",
     "ngx-rangeslider-component": "^1.0.6",
     "rxjs": "~6.3.3",

server/package-lock.json

@@ -9,8 +9,8 @@
   "author": "",
   "license": "ISC",
   "dependencies": {
-    "@sendgrid/mail": "^7.2.6",
     "express": "^4.17.1",
+    "nodemailer": "^6.9.13",
     "nunjucks": "^3.2.0",
     "request": "^2.88.0"
   }