feat: implement comprehensive SSH credentials management system

- Add complete SSH credentials CRUD operations with AES-256 encryption
- Implement database migration system for schema versioning
- Create modern UI with Zinc theme for credentials management
- Add credential viewer and editor with responsive design
- Support password and SSH key authentication methods
- Include usage tracking and folder organization
- Enhance sidebar width and improve page spacing
- Add comprehensive i18n support (EN/ZH)
- Integrate with existing SSH host management

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

public/locales/zh/translation.json

@@ -1,4 +1,103 @@
 {
+  "credentials": {
+    "credentialsManager": "凭据管理器",
+    "manageYourSSHCredentials": "安全管理您的SSH凭据",
+    "addCredential": "添加凭据",
+    "createCredential": "创建凭据",
+    "editCredential": "编辑凭据",
+    "viewCredential": "查看凭据",
+    "duplicateCredential": "复制凭据",
+    "deleteCredential": "删除凭据",
+    "updateCredential": "更新凭据",
+    "credentialName": "凭据名称",
+    "credentialDescription": "描述",
+    "searchCredentials": "搜索凭据...",
+    "selectFolder": "选择文件夹",
+    "selectAuthType": "选择认证类型",
+    "allFolders": "所有文件夹",
+    "allAuthTypes": "所有认证类型",
+    "uncategorized": "未分类",
+    "totalCredentials": "总计",
+    "keyBased": "密钥认证",
+    "passwordBased": "密码认证",
+    "folders": "文件夹",
+    "noCredentialsMatchFilters": "没有符合筛选条件的凭据",
+    "noCredentialsYet": "还未创建凭据",
+    "createFirstCredential": "创建您的第一个凭据",
+    "failedToFetchCredentials": "获取凭据失败",
+    "credentialDeletedSuccessfully": "凭据删除成功",
+    "failedToDeleteCredential": "删除凭据失败",
+    "confirmDeleteCredential": "确定要删除凭据「{{name}}」吗？",
+    "credentialCreatedSuccessfully": "凭据创建成功",
+    "credentialUpdatedSuccessfully": "凭据更新成功",
+    "failedToSaveCredential": "保存凭据失败",
+    "failedToFetchCredentialDetails": "获取凭据详情失败",
+    "failedToFetchHostsUsing": "获取使用此凭据的主机失败",
+    "basicInfo": "基本信息",
+    "authentication": "认证方式",
+    "organization": "组织管理",
+    "basicInformation": "基本信息",
+    "basicInformationDescription": "输入此凭据的基本信息",
+    "authenticationMethod": "认证方式",
+    "authenticationMethodDescription": "选择如何与SSH服务器进行认证",
+    "organizationDescription": "使用文件夹和标签来组织您的凭据",
+    "enterCredentialName": "输入凭据名称",
+    "enterCredentialDescription": "输入描述（可选）",
+    "enterUsername": "输入用户名",
+    "nameIsRequired": "凭据名称是必需的",
+    "usernameIsRequired": "用户名是必需的",
+    "authenticationType": "认证类型",
+    "passwordAuthDescription": "使用密码认证",
+    "sshKeyAuthDescription": "使用SSH密钥认证",
+    "passwordIsRequired": "密码是必需的",
+    "sshKeyIsRequired": "SSH密钥是必需的",
+    "sshKeyType": "SSH密钥类型",
+    "privateKey": "私钥",
+    "enterPassword": "输入密码",
+    "enterPrivateKey": "输入私钥",
+    "keyPassphrase": "密钥密码",
+    "enterKeyPassphrase": "输入密钥密码（可选）",
+    "keyPassphraseOptional": "可选：如果您的密钥没有密码，请留空",
+    "leaveEmptyToKeepCurrent": "留空以保持当前值",
+    "uploadKeyFile": "上传密钥文件",
+    "generateKeyPair": "生成密钥对",
+    "sshKeyGenerationNotImplemented": "SSH密钥生成功能即将推出",
+    "connectionTestingNotImplemented": "连接测试功能即将推出",
+    "testConnection": "测试连接",
+    "selectOrCreateFolder": "选择或创建文件夹",
+    "noFolder": "无文件夹",
+    "orCreateNewFolder": "或创建新文件夹",
+    "addTag": "添加标签",
+    "saving": "保存中...",
+    "overview": "概览",
+    "security": "安全",
+    "usage": "使用情况",
+    "securityDetails": "安全详情",
+    "securityDetailsDescription": "查看加密的凭据信息",
+    "credentialSecured": "凭据已加密",
+    "credentialSecuredDescription": "所有敏感数据均使用AES-256加密",
+    "passwordAuthentication": "密码认证",
+    "keyAuthentication": "密钥认证",
+    "keyType": "密钥类型",
+    "securityReminder": "安全提醒",
+    "securityReminderText": "请勿分享您的凭据。所有数据均已静态加密。",
+    "hostsUsingCredential": "使用此凭据的主机",
+    "noHostsUsingCredential": "当前没有主机使用此凭据",
+    "timesUsed": "使用次数",
+    "lastUsed": "最后使用",
+    "connectedHosts": "连接的主机",
+    "created": "创建时间",
+    "lastModified": "最后修改",
+    "usageStatistics": "使用统计",
+    "copiedToClipboard": "{{field}}已复制到剪贴板",
+    "failedToCopy": "复制到剪贴板失败",
+    "sshKey": "SSH密钥",
+    "createCredentialDescription": "创建新的SSH凭据以进行安全访问",
+    "editCredentialDescription": "更新凭据信息",
+    "listView": "列表",
+    "folderView": "文件夹",
+    "unknown": "未知"
+  },
   "sshTools": {
     "title": "SSH 工具",
     "closeTools": "关闭 SSH 工具",
@@ -120,6 +219,7 @@
   "nav": {
     "home": "首页",
     "hosts": "主机",
+    "credentials": "凭据",
     "terminal": "终端",
     "tunnels": "隧道",
     "fileManager": "文件管理器",