refactor: 架构整固——分层单向化、全量 TypeScript、直接运行

- 移除 bd/mg 两平台及磁盘残留产物；清理 api-test 死脚本、musicSdk/message+options 死模块、infSign vendor
- musicSdk/ 改名 sdk/；src/common、src/auth、src/apis 整体移入 sdk/，依赖方向定为 src → sdk 严格单向
- src/ 手写 JS 全量转 .ts，删除 JS 类型垫片 modules.d.ts；源码 import 统一 .ts 后缀
- Node 原生类型剥离直接运行 .ts（engines >=22.18），取消 tsc 发射产物，tsc 仅类型检查（pnpm typecheck）
- 删除 kwdes 备用实现与 src/index.ts 转发垫片；测试移至 test/smoke-test.ts
- common/request.ts 补显式导出类型；修复 set-cookie 单值形态、ApiError 类字段等隐患

验证：tsc 零错误，smoke-test 41/41

sdk/apis/kg.ts

@@ -0,0 +1,86 @@
+// 酷狗音乐 URL 获取（手机客户端通道）
+// 接口: https://gateway.kugou.com/v5/url（x-router: trackercdn.kugou.com，android 签名）
+// 登录后自动携带 token/userid（见 /login/kg）；匿名仅能获取部分免费资源，
+// VIP/受限资源会返回 status:2。quality: 128k→128, 320k→320, flac→flac, flac24bit→high
+// 统一接口约定：apis('kg').getMusicUrl(songInfo, type) → { promise, cancelHttp }
+// promise resolve → { type, url }
+
+import crypto from 'node:crypto'
+import { httpFetch } from '../common/request.ts'
+import { getKgAuth } from '../auth/store.ts'
+import { androidSign, getDevice } from '../auth/kg.ts'
+
+const md5 = s => crypto.createHash('md5').update(s).digest('hex')
+const SALT_KEY = '57ae12eb6890223e355ccfcb74edf70d'
+const APPID = 1005
+const CLIENTVER = 11430
+
+const qualityMap = { '128k': '128', '320k': '320', flac: 'flac', flac24bit: 'high' }
+
+export const getMusicUrl = (songInfo, type) => {
+  const requestObj = { cancelHttp() {}, promise: null as any }
+  const hash = (songInfo._types?.[type]?.hash || songInfo.hash || '').toLowerCase()
+  if (!hash) {
+    requestObj.promise = Promise.reject(new Error('缺少 hash'))
+    return requestObj
+  }
+
+  requestObj.cancelHttp = () => {} // 单次 GET，无需取消
+
+  requestObj.promise = (async() => {
+    const dev = getDevice()
+    const auth = getKgAuth()
+    const userid = Number(auth?.userid || 0)
+
+    const params: Record<string, any> = {
+      dfid: dev.dfid, mid: dev.mid, uuid: '-', appid: APPID, clientver: CLIENTVER,
+      clienttime: Math.floor(Date.now() / 1000),
+      album_id: Number(songInfo.albumId ?? 0),
+      area_code: 1,
+      hash,
+      ssa_flag: 'is_fromtrack',
+      version: CLIENTVER,
+      page_id: 151369488,
+      quality: qualityMap[type] ?? '128',
+      album_audio_id: Number(songInfo.songmid ?? 0),
+      behavior: 'play',
+      pid: 2,
+      cmd: 26,
+      pidversion: 3001,
+      IsFreePart: 0,
+      ppage_id: '463467626,350369493,788954147',
+      cdnBackup: 1,
+      module: '',
+    }
+    if (auth) {
+      params.token = auth.token
+      params.userid = userid
+    }
+    params.key = md5(`${hash}${SALT_KEY}${APPID}${dev.mid}${userid}`)
+    params.signature = androidSign(params)
+
+    const qs = Object.keys(params).map(k => `${k}=${encodeURIComponent(params[k])}`).join('&')
+    const r = await httpFetch(`https://gateway.kugou.com/v5/url?${qs}`, {
+      method: 'get',
+      headers: {
+        dfid: dev.dfid, mid: dev.mid, clienttime: String(params.clienttime),
+        'kg-rc': '1', 'kg-thash': '5d816a0', 'kg-rec': '1', 'kg-rf': 'B9EDA08A64250DEFFBCADDEE00F8F25F',
+        'x-router': 'trackercdn.kugou.com',
+        'User-Agent': 'Android15-1070-11083-46-0-DiscoveryDRADProtocol-wifi',
+      },
+      timeout: 15000,
+    }).promise
+
+    const body = r.body && typeof r.body === 'object' ? r.body : {}
+    if (body.status !== 1 || !Array.isArray(body.data)) {
+      throw new Error(body.error || (auth ? '获取失败' : '获取失败（该资源需要酷狗登录）'))
+    }
+    const item = body.data.find(d => d.url) ?? body.data[0]
+    const url = item?.url || item?.fallback
+    if (!url) throw new Error('获取失败')
+    return { type, url }
+  })()
+  return requestObj
+}
+
+export default { getMusicUrl }