feat(site): tighten proof, contact, and inquiry delivery

Lead with Batch on the home page, drop the product changelog, add a
domain note, and stop reporting success when SMTP fails.

Co-authored-by: Cursor <cursoragent@cursor.com>

package.json

@@ -7,7 +7,7 @@
     "build": "next build",
     "start": "next start",
     "lint": "eslint",
-    "test": "node --experimental-strip-types --test src/i18n/routes.test.ts src/lib/contact/schema.test.ts"
+    "test": "node --experimental-strip-types --test src/i18n/routes.test.ts src/lib/contact/schema.test.ts src/lib/contact/deliver.test.ts"
   },
   "dependencies": {
     "next": "16.3.1",