Fix payment QR preview rendering using inline data URIs.

Match Events/QR Plus pattern so QR images render without a separate authenticated preview URL, and add a styled preview card on the show page.

Co-authored-by: Cursor <cursoragent@cursor.com>

resources/views/mini/payment-qrs/create.blade.php

@@ -1,7 +1,18 @@
 <x-user-layout>
     <x-slot name="title">Create Payment QR</x-slot>
     <div class="mx-auto max-w-2xl space-y-6">
-        <div>
+        <div class="flex items-center gap-3 py-1 lg:hidden">
+            <a href="{{ route('mini.payment-qrs.index') }}"
+               class="flex h-9 w-9 shrink-0 items-center justify-center rounded-xl border border-slate-200 bg-white text-slate-500 shadow-sm transition hover:text-slate-900">
+                <svg class="h-4 w-4" fill="none" stroke="currentColor" stroke-width="2" viewBox="0 0 24 24">
+                    <path stroke-linecap="round" stroke-linejoin="round" d="M15.75 19.5 8.25 12l7.5-7.5"/>
+                </svg>
+            </a>
+            <img src="{{ asset('images/logo/ladillmini-logo.svg') }}?v={{ @filemtime(public_path('images/logo/ladillmini-logo.svg')) ?: '1' }}"
+                 alt="Ladill Mini" class="h-5 w-auto shrink-0">
+            <span class="min-w-0 flex-1 truncate text-sm font-semibold text-slate-900">Create payment QR</span>
+        </div>
+        <div class="hidden lg:block">
             <a href="{{ route('mini.payment-qrs.index') }}" class="text-sm text-slate-500 hover:text-slate-700">← Back to payment QRs</a>
             <h1 class="mt-2 text-xl font-semibold text-slate-900">Create payment QR</h1>
             <p class="mt-1 text-sm text-slate-500">Customers scan, enter an amount, and pay. Your QR is generated automatically — no styling needed.</p>