feat: 优化跟单买入逻辑和错误处理

- 更新 Twitter 链接为 @polyhermes
- 简化订单创建失败日志，只保留 code 和 errorBody
- 修复 @Transactional 注解问题（类改为 open class）
- 改进唯一键冲突异常处理，支持并发场景
- 整理跟单买入和重试逻辑，使用常量配置
- 重试延迟从 1 秒调整为 3 秒
- 添加订单簿匹配检查，避免 FAK 订单失败
- 前端移除 Leader 管理的分类相关设置和显示
- 补充多语言翻译（AccountImport 和 CopyTradingList）

frontend/src/locales/en/common.json

@@ -856,6 +856,8 @@
   "copyTradingList": {
     "title": "Copy Trading Config Management",
     "addCopyTrading": "Add Copy Trading",
+    "configName": "Config Name",
+    "configNameNotProvided": "Not Provided",
     "wallet": "Wallet",
     "account": "Account",
     "template": "Template",

frontend/src/locales/zh-CN/common.json

@@ -117,19 +117,40 @@
   },
   "accountImport": {
     "title": "导入账户",
+    "back": "返回",
+    "securityTip": "安全提示",
+    "securityTipDesc": "私钥将存储在后端数据库中，请确保数据库访问安全。建议使用 HTTPS 连接。",
+    "importMethod": "导入方式",
     "privateKey": "私钥",
+    "mnemonic": "助记词",
+    "privateKeyLabel": "私钥",
+    "privateKeyPlaceholder": "请输入私钥（64位十六进制字符串，可选0x前缀）",
     "privateKeyRequired": "请输入私钥",
-    "privateKeyPlaceholder": "请输入或粘贴私钥",
-    "privateKeyHelp": "私钥将加密存储，仅用于签名交易",
+    "privateKeyInvalid": "私钥格式不正确（应为64位十六进制字符串）",
+    "walletAddress": "钱包地址",
+    "walletAddressPlaceholder": "钱包地址（将从私钥自动推导）",
+    "walletAddressRequired": "请输入钱包地址",
+    "walletAddressInvalid": "钱包地址格式不正确",
+    "walletAddressMismatch": "钱包地址与私钥不匹配",
+    "mnemonicLabel": "助记词",
+    "mnemonicPlaceholder": "请输入12或24个单词的助记词（用空格分隔）",
+    "mnemonicRequired": "请输入助记词",
+    "mnemonicInvalid": "助记词格式不正确（应为12或24个单词，用空格分隔）",
+    "walletAddressMismatchMnemonic": "钱包地址与助记词不匹配",
     "accountName": "账户名称",
     "accountNameRequired": "请输入账户名称",
-    "accountNamePlaceholder": "请输入账户名称",
+    "accountNamePlaceholder": "可选，用于标识账户",
     "accountNameHelp": "用于标识账户，便于管理",
+    "privateKeyHelp": "私钥将加密存储，仅用于签名交易",
     "submit": "导入",
+    "invalidPrivateKey": "无效的私钥",
+    "duplicateAccount": "账户已存在",
+    "importAccount": "导入账户",
     "importSuccess": "导入账户成功",
     "importFailed": "导入账户失败",
-    "invalidPrivateKey": "无效的私钥",
-    "duplicateAccount": "账户已存在"
+    "derivedAddress": "推导地址",
+    "addressError": "无法从私钥推导地址",
+    "addressErrorMnemonic": "无法从助记词推导地址"
   },
   "leader": {
     "title": "Leader 管理",

frontend/src/locales/zh-TW/common.json

@@ -856,6 +856,8 @@
   "copyTradingList": {
     "title": "跟單配置管理",
     "addCopyTrading": "新增跟單",
+    "configName": "配置名",
+    "configNameNotProvided": "未提供",
     "wallet": "錢包",
     "account": "賬戶",
     "template": "模板",