Phase6c: Optional Company contact name

src/messages/en.json

@@ -504,7 +504,9 @@
     "invalidCountry": "Country code must be 2 letters (e.g. CH).",
     "invalidEmail": "Please enter a valid email address.",
     "fullNameLabel": "Full name",
-    "subtitlePersonal": "Your billing address and invoice contact. Required before invoices can be issued."
+    "subtitlePersonal": "Your billing address and invoice contact. Required before invoices can be issued.",
+    "contactNameLabel": "Contact person (optional)",
+    "contactNameHint": "Prints as 'Attn: <name>' on the invoice below the company name. Useful for AP routing in larger organizations."
   },
   "support": {
     "title": "Support",