fix: 分站价格单位改为每1M tokens + 移除所有SubRouter主站标识

- 价格表单位从 "per 1K tokens" 改为 "per 1M tokens"（价格×1000显示）
- 移除 footer "Powered by SubRouter" 字样
- 默认站名从 "SubRouter" 改为 "AI Platform"
- HTML title 从 "SubRouter Dist Site" 改为 "AI Platform"
- 分站不再包含任何主站品牌标识

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

index.html

@@ -6,7 +6,7 @@
     <link rel="preconnect" href="https://fonts.googleapis.com" />
     <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=JetBrains+Mono:wght@400;500&display=swap" rel="stylesheet" />
-    <title>SubRouter Dist Site</title>
+    <title>AI Platform</title>
   </head>
   <body class="bg-black text-white antialiased">
     <div id="root"></div>