feat(frontend): 支持批量编辑和管理已保存登录凭证

为连接表单补充已保存登录凭证的校验与提交流程，
允许新增、批量新增、测试连接时优先使用凭证

在连接列表中新增登录凭证管理入口，并支持批量编辑
时按连接类型筛选和应用已保存凭证

补充中英日文案，并修复 SSH 密钥选择器的绑定兼容性

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

@@ -217,6 +217,8 @@
       "title": "批量编辑连接",
       "selectedItems": "已选项目",
       "noChange": "保持不变",
+      "savedCredentialMixedType": "批量应用已保存凭证前，请先只选择同一种连接类型。",
+      "savedCredentialTypeHint": "仅支持同类型连接批量应用",
       "deleteSelectedButton": "删除选中",
       "deleteSelectedTooltip": "删除选中的连接",
       "confirmMessage": "您确定要删除选中的 {count} 个连接吗？此操作无法撤销。",
@@ -273,6 +275,23 @@
       "connectionModeProxy": "代理服务器",
       "connectionModeJumpHost": "跳板机",
       "connectionType": "连接类型",
+      "credentialSource": "认证来源",
+      "credentialSourceDirect": "账号密码 / 密钥",
+      "credentialSourceSaved": "使用已保存凭证",
+      "savedLoginCredential": "登录凭证",
+      "selectLoginCredential": "请选择登录凭证",
+      "manageLoginCredentials": "管理登录凭证",
+      "savedCredentialHint": "已保存凭证会在连接和测试时优先使用；切回直填后仍可继续手工输入。",
+      "loginCredentialManager": "登录凭证",
+      "addLoginCredential": "新增登录凭证",
+      "editLoginCredential": "编辑登录凭证",
+      "noLoginCredentials": "暂无登录凭证",
+      "clearSavedCredential": "取消已保存凭证",
+      "errorLoginCredentialRequired": "请选择已保存的登录凭证。",
+      "errorCredentialRequiredFields": "名称和用户名为必填项。",
+      "errorCredentialDetails": "获取登录凭证详情失败。",
+      "confirmDeleteCredential": "确认删除登录凭证 {name}？",
+      "errorDeleteCredential": "删除登录凭证失败。",
       "typeSsh": "SSH",
       "typeRdp": "RDP",
       "typeVnc": "VNC",