fix(mcp): improve format/submit UX and fix validation errors

Fixes two critical issues with the MCP JSON input:
1. Format button failed with wrapped format like "server": {...}
2. Submit button failed despite input validation passing

Changes:
- Updated formatJSON to use smart parser (supports wrapped format)
- Simplified submit validation logic (removed redundant validateJsonConfig call)
- Improved UX: input preserves original format, cleanup happens on format/submit
  * Prevents confusing "instant disappearance" when pasting wrapped JSON
  * Auto-fills ID/Name fields while keeping input unchanged
  * Format button now strips wrapper key and formats cleanly
  * Submit button correctly extracts config regardless of format

Code quality:
- Reduced code by 5 lines (20 changes, 11 insertions, 16 deletions)
- Consistent use of parseSmartMcpJson across all JSON operations
- No type errors introduced

src/utils/formatters.ts

@@ -1,6 +1,6 @@
 /**
  * 格式化 JSON 字符串
- * @param value - 原始 JSON 字符串
+ * @param value - 原始 JSON 字符串（支持带键名包装的格式）
  * @returns 格式化后的 JSON 字符串（2 空格缩进）
  * @throws 如果 JSON 格式无效
  */
@@ -9,8 +9,9 @@ export function formatJSON(value: string): string {
   if (!trimmed) {
     return "";
   }
-  const parsed = JSON.parse(trimmed);
-  return JSON.stringify(parsed, null, 2);
+  // 使用智能解析器来处理可能的片段格式
+  const result = parseSmartMcpJson(trimmed);
+  return result.formattedConfig;
 }
 
 /**