feat(qs): 汽水音乐平台接入——匿名搜索/试听、抖音扫码登录、解密流代理

- sdk/qs 平台模块(安卓参数指纹匿名搜索)+ sdk/apis/qs 取流:
  匿名 30s 试听,登录态走签名 track_v2 + spade key AES-CTR 解密
- /login/qs/qr 抖音扫码登录(授权后 sessionid 解锁完整曲目)
- /stream/qs/:id 解密流代理,/url 返回的相对地址按请求 host 补全
- 回归测试覆盖 kw 双通道(VIP 真音频/降级链)与 qs 试听;start.bat 去掉
  SOURCE_ENABLED 直启

sdk/qs/crypto/ttencrypt.ts

@@ -0,0 +1,26 @@
+// TT 加密（设备注册请求体）：gzip + SHA512 校验 + AES-128-CBC，magic 头 "tc"
+// 移植自 fanqie-assistant src/crypto/ttencrypt.ts（Node crypto 实现）
+import { createCipheriv, createHash, randomBytes } from 'node:crypto'
+import { gzipSync } from 'node:zlib'
+
+// 固定盐（base64 常量，社区共知）
+const FIXED_STRING = Buffer.from(
+  'TdTC5rgxYgkOUrPHpnM7pByyRiuCmrWKGWs521cXdST0m69/COjWjSanLjfBqVovHwWlGJKu8pSXMrYqOKrdWA==',
+  'base64',
+)
+
+const sha512 = (data: Buffer): Buffer => createHash('sha512').update(data).digest()
+
+export const encryptTT = (data: Buffer): Buffer => {
+  const rand = randomBytes(32)
+  const hashValue = sha512(Buffer.concat([sha512(rand), FIXED_STRING]))
+  const key = hashValue.subarray(0, 16)
+  const iv = hashValue.subarray(16, 32)
+  const compressed = gzipSync(data)
+  const payload = Buffer.concat([sha512(compressed), compressed])
+  const cipher = createCipheriv('aes-128-cbc', key, iv)
+  const encrypted = Buffer.concat([cipher.update(payload), cipher.final()])
+  return Buffer.concat([Buffer.from([116, 99, 5, 16, 0, 0]), rand, encrypted])
+}
+
+export default { encryptTT }