Afia: rebrand merchant assistant from QR Plus/Give to Merchant

The merchant app shipped the QR Plus Afia: the chat panel subtitle read
'Give assistant' and the system prompt identified as 'Ladill QR Plus' and
described QR-code features (Link/PDF/WiFi/styling) instead of this app's
storefronts. Rewrite the prompt for Ladill Merchant (storefronts —
shop/menu/booking, orders, payouts, fees) and fix the subtitle to
'Merchant assistant'.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

resources/views/partials/afia.blade.php

@@ -48,7 +48,7 @@
                 </span>
                 <div class="leading-tight">
                     <p class="text-sm font-semibold text-slate-900">Afia</p>
-                    <p class="text-[11px] text-slate-400">Give assistant</p>
+                    <p class="text-[11px] text-slate-400">Merchant assistant</p>
                 </div>
             </div>
             <div class="flex items-center gap-1">