Add bnfexpress signed admin client and AI Agent Filament UI

- Modules\Shared\Bnfexpress\BnfexpressAdminClient: HMAC-signed HTTP client
  for bnfexpress's admin API (EV FAQs, agent instructions, chat history),
  with a bnfexpress:smoke-test command and full unit coverage.
- New ai-agent module: Filament pages to manage EV FAQs, publish/roll back
  agent instruction versions, and browse EV chat history + transcripts.
- New manage_ai_agent permission (super_admin/admin).
- Recorded .ai/rules for the client's auth scheme and non-Resource
  Filament page/table testing gotchas.

app-modules/ai-agent/resources/views/filament/pages/partials/transcript.blade.php

@@ -0,0 +1,34 @@
+@php
+    $labels = [
+        'user' => 'User',
+        'bnfexpress_ev_agent' => 'Assistant',
+    ];
+@endphp
+
+<div class="max-h-[32rem] space-y-3 overflow-y-auto">
+    @forelse (($transcript['messages'] ?? []) as $message)
+        @php
+            $author = $message['author'] ?? 'unknown';
+            $isUser = $author === 'user';
+        @endphp
+        <div @class([
+            'max-w-[85%] rounded-lg border p-3',
+            'ms-auto border-primary-200 bg-primary-50 dark:border-primary-800 dark:bg-primary-950' => $isUser,
+            'border-gray-200 bg-gray-50 dark:border-gray-700 dark:bg-gray-800' => ! $isUser,
+        ])>
+            <div class="mb-1 flex items-center justify-between gap-3">
+                <span class="text-xs font-medium uppercase text-gray-500 dark:text-gray-400">
+                    {{ $labels[$author] ?? $author }}
+                </span>
+                @if (isset($message['timestamp']))
+                    <span class="text-xs text-gray-400 dark:text-gray-500">
+                        {{ \Illuminate\Support\Carbon::createFromTimestamp($message['timestamp'])->format('M j, Y g:i A') }}
+                    </span>
+                @endif
+            </div>
+            <p class="whitespace-pre-wrap text-sm">{{ $message['text'] ?? '' }}</p>
+        </div>
+    @empty
+        <p class="text-sm text-gray-500">No messages in this session.</p>
+    @endforelse
+</div>