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>

app/ui/AccountForm.tsx

@@ -25,6 +25,12 @@ const FormFields: FC<FormFieldsProps> = ({ profile, errors, message }) => {
 
     return (
         <>
+            <div className="alert max-w-md flex flex-row items-start">
+                <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" className="stroke-current shrink-0 w-6 h-6">
+                    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth="2" d="M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"></path>
+                </svg>
+                <span className="text-left">{t("info-box-message")}</span>
+            </div>
             <div className="form-control w-full">
                 <label className="label">
                     <span className="label-text">{t("first-name-label")}</span>