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/wy.ts

@@ -0,0 +1,48 @@
+// 网易云音乐 URL 获取（直连）
+// 接口: https://interface3.music.163.com/eapi/song/enhance/player/url/v1（eapi 加密请求，响应为明文 JSON）
+// 音质: 128k → standard, 320k → exhigh, flac → lossless
+// 统一接口约定：apis('wy').getMusicUrl(songInfo, type) → { promise, cancelHttp }
+// promise resolve → { type, url }
+
+import { httpFetch } from '../common/request.ts'
+// crypto.js 为 tsc 就地发射产物（源 sdk/wy/utils/crypto.ts）；统一走 .js，避免同进程出现 .ts/.js 双实例
+import { eapi } from '../wy/utils/crypto.ts'
+import { getWyCookie } from '../auth/store.ts'
+
+const levelMap = {
+  '128k': 'standard',
+  '320k': 'exhigh',
+  flac: 'lossless',
+  flac24bit: 'hires',
+}
+
+export const getMusicUrl = (songInfo, type) => {
+  const requestObj = { cancelHttp() {}, promise: null as any }
+  const data = {
+    ids: `[${songInfo.songmid}]`,
+    level: levelMap[type] || 'standard',
+    encodeType: 'flac',
+  }
+  const cookie = getWyCookie()
+  const request = httpFetch('https://interface3.music.163.com/eapi/song/enhance/player/url/v1', {
+    method: 'post',
+    headers: {
+      'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
+      origin: 'https://music.163.com',
+      ...(cookie ? { cookie } : {}),
+    },
+    form: eapi('/api/song/enhance/player/url/v1', data),
+    timeout: 15000,
+  })
+  requestObj.promise = request.promise.then(({ statusCode, body }) => {
+    if (statusCode != 200 || body.code != 200) {
+      return Promise.reject(new Error('获取失败'))
+    }
+    const item = body.data?.[0]
+    if (!item?.url) return Promise.reject(new Error('获取失败'))
+    return { type, url: item.url }
+  })
+  return requestObj
+}
+
+export default { getMusicUrl }