Remove lastName field from UserSettings and database

- Removed lastName from UserSettings interface
- Updated UserSettingsForm to remove lastName input field
- Removed lastName from all database operations
- Updated form validation schema to remove lastName validation
- Updated ViewLocationCard to use only firstName for recipient name
- Removed lastName from user settings form state tracking
- Updated Croatian translations to reflect changes

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

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

app/ui/UserSettingsForm.tsx

@@ -28,7 +28,6 @@ const FormFields: FC<FormFieldsProps> = ({ userSettings, errors, message }) => {
     // Track current form values for real-time validation
     const [formValues, setFormValues] = useState({
         firstName: userSettings?.firstName ?? "",
-        lastName: userSettings?.lastName ?? "",
         street: userSettings?.street ?? "",
         town: userSettings?.town ?? "",
         iban: formatIban(userSettings?.iban) ?? "",
@@ -41,7 +40,7 @@ const FormFields: FC<FormFieldsProps> = ({ userSettings, errors, message }) => {
 
     // Check if any required field is missing (clean IBAN of spaces for validation)
     const cleanedIban = formValues.iban.replace(/\s/g, '');
-    const hasMissingData = !formValues.firstName || !formValues.lastName || !formValues.street || !formValues.town || !cleanedIban || !formValues.currency;
+    const hasMissingData = !formValues.firstName || !formValues.street || !formValues.town || !cleanedIban || !formValues.currency;
 
     // Track whether to generate 2D code for tenant (use persisted value from database)
     const [show2dCodeInMonthlyStatement, setShow2dCodeInMonthlyStatement] = useState(
@@ -94,30 +93,6 @@ const FormFields: FC<FormFieldsProps> = ({ userSettings, errors, message }) => {
                         </div>
                     </div>
 
-                    <div className="form-control w-full">
-                        <label className="label">
-                            <span className="label-text">{t("last-name-label")}</span>
-                        </label>
-                        <input
-                            id="lastName"
-                            name="lastName"
-                            type="text"
-                            placeholder={t("last-name-placeholder")}
-                            className="input input-bordered w-full placeholder:text-gray-600"
-                            defaultValue={userSettings?.lastName ?? ""}
-                            onChange={(e) => handleInputChange("lastName", e.target.value)}
-                            disabled={pending}
-                        />
-                        <div id="lastName-error" aria-live="polite" aria-atomic="true">
-                            {errors?.lastName &&
-                                errors.lastName.map((error: string) => (
-                                    <p className="mt-2 text-sm text-red-500" key={error}>
-                                        {error}
-                                    </p>
-                                ))}
-                        </div>
-                    </div>
-
                     <div className="form-control w-full">
                         <label className="label">
                             <span className="label-text">{t("street-label")} </span>