feat: 移除 JSON 格式化页面，更新 MTR 表单和工具列表

src/lib/tools.ts

@@ -9,15 +9,5 @@ export const tools: Tool[] = [
     title: "Rail Transit Guide",
     description: "轨道交通导视生成器",
     href: "/rt-guide",
-  },
-  {
-    title: "URL Encoder/Decoder",
-    description: "Encode or decode URLs and strings.",
-    href: "/url-encoder",
-  },
-  {
-    title: "Base64 Encoder/Decoder",
-    description: "Encode or decode strings to and from Base64.",
-    href: "/base64-encoder",
-  },
+  }
 ];