Add wallet balance widget to the profile menu (after Billing)

Wallet balance peek rendered as a menu row directly under Billing, backed by
a /wallet/balance endpoint (BillingClient) and guarded by Route::has. Also
opens Afia via a direct window event for reliability.

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

resources/views/partials/afia-button.blade.php

@@ -8,7 +8,7 @@
             @if ($handler === 'openAfia')
                 @click="openAfia()"
             @else
-                @click="$dispatch('afia-open')"
+                @click="window.dispatchEvent(new CustomEvent('afia-open'))"
             @endif
             @class([
                 'inline-flex shrink-0 items-center justify-center gap-2 rounded-xl bg-gradient-to-r from-indigo-700 via-blue-600 to-emerald-400 text-sm font-semibold text-white shadow-sm transition hover:opacity-95',