feat: v0.3.0 版本 - SSH终端、SFTP、端口转发功能实现

核心功能:
- SSH终端: 密码/密钥认证、XTerm.js终端、多主题配色、IP高亮
- SFTP管理: 双栏文件管理、上传下载、传输队列
- 端口转发: 本地/远程转发、SOCKS5动态代理、规则管理

架构改进:
- 拆分大型组件 (SFTPView/TabBar/Sidebar)
- 添加统一日志和错误处理
- 修复React严格模式下的终端黑屏问题

UI更新:
- 新增端口转发视图
- 更新UI预览文档
- 左侧栏右键菜单支持SFTP快捷打开

electron/services/crypto.ts

@@ -0,0 +1,95 @@
+import crypto from 'crypto'
+
+const ALGORITHM = 'aes-256-gcm'
+const KEY_LENGTH = 32
+const IV_LENGTH = 16
+const TAG_LENGTH = 16
+const SALT_LENGTH = 32
+const ITERATIONS = 100000
+
+// 从密码派生密钥
+function deriveKey(password: string, salt: Buffer): Buffer {
+  return crypto.pbkdf2Sync(password, salt, ITERATIONS, KEY_LENGTH, 'sha256')
+}
+
+// 生成随机密钥（用于主密钥）
+export function generateMasterKey(): string {
+  return crypto.randomBytes(KEY_LENGTH).toString('hex')
+}
+
+// 加密数据
+export function encrypt(plaintext: string, password: string): string {
+  const salt = crypto.randomBytes(SALT_LENGTH)
+  const key = deriveKey(password, salt)
+  const iv = crypto.randomBytes(IV_LENGTH)
+
+  const cipher = crypto.createCipheriv(ALGORITHM, key, iv)
+  const encrypted = Buffer.concat([cipher.update(plaintext, 'utf8'), cipher.final()])
+  const tag = cipher.getAuthTag()
+
+  // 格式: salt:iv:tag:encrypted (全部 hex)
+  return [
+    salt.toString('hex'),
+    iv.toString('hex'),
+    tag.toString('hex'),
+    encrypted.toString('hex'),
+  ].join(':')
+}
+
+// 解密数据
+export function decrypt(ciphertext: string, password: string): string {
+  try {
+    const [saltHex, ivHex, tagHex, encryptedHex] = ciphertext.split(':')
+
+    if (!saltHex || !ivHex || !tagHex || !encryptedHex) {
+      throw new Error('Invalid ciphertext format')
+    }
+
+    const salt = Buffer.from(saltHex, 'hex')
+    const iv = Buffer.from(ivHex, 'hex')
+    const tag = Buffer.from(tagHex, 'hex')
+    const encrypted = Buffer.from(encryptedHex, 'hex')
+
+    const key = deriveKey(password, salt)
+
+    const decipher = crypto.createDecipheriv(ALGORITHM, key, iv)
+    decipher.setAuthTag(tag)
+
+    const decrypted = Buffer.concat([decipher.update(encrypted), decipher.final()])
+    return decrypted.toString('utf8')
+  } catch (error) {
+    throw new Error('Decryption failed: ' + (error as Error).message)
+  }
+}
+
+// 简单加密（不带 salt，用于可逆加密）
+export function simpleEncrypt(plaintext: string, key: string): string {
+  const iv = crypto.randomBytes(IV_LENGTH)
+  const keyBuffer = Buffer.from(key, 'hex').slice(0, KEY_LENGTH)
+
+  const cipher = crypto.createCipheriv(ALGORITHM, keyBuffer, iv)
+  const encrypted = Buffer.concat([cipher.update(plaintext, 'utf8'), cipher.final()])
+  const tag = cipher.getAuthTag()
+
+  return iv.toString('hex') + ':' + tag.toString('hex') + ':' + encrypted.toString('hex')
+}
+
+// 简单解密
+export function simpleDecrypt(ciphertext: string, key: string): string {
+  try {
+    const [ivHex, tagHex, encryptedHex] = ciphertext.split(':')
+
+    const iv = Buffer.from(ivHex, 'hex')
+    const tag = Buffer.from(tagHex, 'hex')
+    const encrypted = Buffer.from(encryptedHex, 'hex')
+    const keyBuffer = Buffer.from(key, 'hex').slice(0, KEY_LENGTH)
+
+    const decipher = crypto.createDecipheriv(ALGORITHM, keyBuffer, iv)
+    decipher.setAuthTag(tag)
+
+    const decrypted = Buffer.concat([decipher.update(encrypted), decipher.final()])
+    return decrypted.toString('utf8')
+  } catch (error) {
+    throw new Error('Decryption failed: ' + (error as Error).message)
+  }
+}