UI: Center-align PDF417 barcode within label containers

Added justify-center class to label elements containing Pdf417Barcode
component for better visual alignment.

Changes:
- BillEditForm: Center barcode in form display
- ViewBillCard: Center barcode in read-only view

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

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

app/ui/BillEditForm.tsx

@@ -211,7 +211,7 @@ export const BillEditForm: FC<BillEditFormProps> = ({ location, bill }) => {
                     {
                         hub3aText ?
                             <div className="form-control p-1">
-                                <label className="cursor-pointer label p-2 grow bg-white">
+                                <label className="label p-2 grow bg-white border border-gray-300 rounded-box justify-center">
                                     <Pdf417Barcode hub3aText={hub3aText} />
                                 </label>
                                 <p className="text-xs my-1">{t.rich('barcode-disclaimer', { br: () => <br /> })}</p>

app/ui/ViewBillCard.tsx

@@ -61,7 +61,7 @@ export const ViewBillCard:FC<ViewBillCardProps> = ({ location, bill }) => {
             {
                 hub3aText ?
                     <div className="form-control p-1">
-                        <label className="cursor-pointer label p-2 grow bg-white">
+                        <label className="cursor-pointer label p-2 grow bg-white justify-center">
                             <Pdf417Barcode hub3aText={hub3aText} />
                         </label>
                         <p className="text-xs my-1">{t.rich('barcode-disclaimer', { br: () => <br /> })}</p>