Add info box to account form explaining barcode usage

Added informational alert at the top of the account form to explain
that profile data (name, address, IBAN) will be used to generate 2D
barcodes for tenant bill payments. The alert uses a horizontal layout
on all screen sizes for consistent UX.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

messages/hr.json

@@ -137,6 +137,7 @@
   },
   "account-form": {
     "title": "Podaci o profilu",
+    "info-box-message": "Ovi podaci će se koristiti za generiranje 2D barkoda koji će biti prikazan u pregledu računa, omogućujući podstanarima da ga skeniraju i vrate novac koji ste potrošili na plaćanje režija u njihovo ime.",
     "first-name-label": "Ime",
     "first-name-placeholder": "Unesite svoje ime",
     "last-name-label": "Prezime",