🐛 fix(dameng): 修复特殊字符密码导致连接认证失败

- 调整达梦 DSN 生成逻辑，密码按驱动解析规则原样传入
- 移除默认 escapeProcess 参数示例，避免误导配置
- 补充特殊字符密码与问号密码的回归测试
Refs #446

frontend/src/components/ConnectionModal.tsx

@@ -1853,7 +1853,7 @@ const ConnectionModal: React.FC<{
       case "mongodb":
         return "retryWrites=true&readPreference=secondaryPreferred";
       case "dameng":
-        return "schema=SYSDBA&escapeProcess=true";
+        return "schema=SYSDBA";
       case "tdengine":
         return "timezone=Asia%2FShanghai";
       default: