Remove tenantLastName field from LocationEditForm and database

- Removed tenantLastName from BillingLocation interface
- Updated LocationEditForm to remove tenantLastName input field
- Removed tenantLastName from all database operations (insert and update)
- Updated form validation schema to remove tenantLastName validation
- Updated ViewLocationCard to use only tenantFirstName for payer name
- Removed tenantLastName from tenant field state tracking

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

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

app/ui/LocationEditForm.tsx

@@ -46,7 +46,6 @@ export const LocationEditForm: FC<LocationEditFormProps> = ({ location, yearMont
     // Track tenant field values for real-time validation
     const [tenantFields, setTenantFields] = useState({
         tenantFirstName: location?.tenantFirstName ?? "",
-        tenantLastName: location?.tenantLastName ?? "",
         tenantStreet: location?.tenantStreet ?? "",
         tenantTown: location?.tenantTown ?? "",
         tenantEmail: location?.tenantEmail ?? "",
@@ -123,29 +122,6 @@ export const LocationEditForm: FC<LocationEditFormProps> = ({ location, yearMont
                                     </div>
                                 </div>
 
-                                <div className="form-control w-full">
-                                    <label className="label">
-                                        <span className="label-text">{t("tenant-last-name-label")}</span>
-                                    </label>
-                                    <input
-                                        id="tenantLastName"
-                                        name="tenantLastName"
-                                        type="text"
-                                        placeholder={t("tenant-last-name-placeholder")}
-                                        className="input input-bordered w-full placeholder:text-gray-600"
-                                        defaultValue={location?.tenantLastName ?? ""}
-                                        onChange={(e) => handleTenantFieldChange("tenantLastName", e.target.value)}
-                                    />
-                                    <div id="tenantLastName-error" aria-live="polite" aria-atomic="true">
-                                        {state.errors?.tenantLastName &&
-                                            state.errors.tenantLastName.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("tenant-street-label")}</span>