feat(mcp): enhance wizard with title field and optimize placeholders

- Add MCP title field to wizard (required)
- Remove working directory (cwd) field and related logic
- Update wizard callback to return both title and JSON
- Optimize placeholder text for better user guidance:
  - Command: "npx or uvx"
  - Args: "arg1\narg2"
  - Env: "KEY1=value1\nKEY2=value2"
  - Headers: "Authorization: Bearer your_token_here\n..."
- Simplify args label by removing "(one per line)" hint
- Update parent component to handle title from wizard

src/i18n/locales/zh.json

@@ -292,24 +292,21 @@
       "hint": "快速配置 MCP 服务器，自动生成 JSON 配置",
       "type": "类型",
       "command": "命令",
-      "commandPlaceholder": "uvx",
-      "args": "参数（每行一个）",
-      "argsPlaceholder": "mcp-server-fetch\n--config config.json",
-      "cwd": "工作目录",
-      "cwdPlaceholder": "/path/to/project",
+      "commandPlaceholder": "npx 或 uvx",
+      "args": "参数",
+      "argsPlaceholder": "arg1\narg2",
       "env": "环境变量",
-      "envPlaceholder": "KEY=VALUE\n(一行一个)",
+      "envPlaceholder": "KEY1=value1\nKEY2=value2",
       "url": "URL",
       "urlPlaceholder": "https://api.example.com/mcp",
       "urlRequired": "请输入 URL",
       "headers": "请求头（可选）",
-      "headersPlaceholder": "Authorization: Bearer token\nContent-Type: application/json",
+      "headersPlaceholder": "Authorization: Bearer your_token_here\nContent-Type: application/json",
       "preview": "配置预览",
       "apply": "应用配置"
     },
     "id": "标识 (唯一)",
     "type": "类型",
-    "cwd": "工作目录 (可选)",
     "command": "命令",
     "validateCommand": "校验命令",
     "args": "参数",