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/kg/musicSearch.ts

@@ -0,0 +1,109 @@
+import { httpFetch } from '../request.ts'
+import { decodeName, formatPlayTime, sizeFormate } from '../index.ts'
+import { formatSingerName } from '../utils.ts'
+import type { SongType, QualityInfo } from '../types.ts'
+
+
+export default {
+  limit: 30,
+  total: 0,
+  page: 0,
+  allPage: 1,
+  musicSearch(str, page, limit) {
+    const searchRequest = httpFetch(`https://songsearch.kugou.com/song_search_v2?keyword=${encodeURIComponent(str)}&page=${page}&pagesize=${limit}&userid=0&clientver=&platform=WebFilter&filter=2&iscorrection=1&privilege_filter=0&area_code=1`)
+    return searchRequest.promise.then(({ body }) => body)
+  },
+  filterData(rawData) {
+    const types: Array<SongType & { hash?: string }> = []
+    const _types: Record<string, QualityInfo & { hash?: string }> = {}
+    if (rawData.FileSize !== 0) {
+      let size = sizeFormate(rawData.FileSize)
+      types.push({ type: '128k', size, hash: rawData.FileHash })
+      _types['128k'] = {
+        size,
+        hash: rawData.FileHash,
+      }
+    }
+    if (rawData.HQFileSize !== 0) {
+      let size = sizeFormate(rawData.HQFileSize)
+      types.push({ type: '320k', size, hash: rawData.HQFileHash })
+      _types['320k'] = {
+        size,
+        hash: rawData.HQFileHash,
+      }
+    }
+    if (rawData.SQFileSize !== 0) {
+      let size = sizeFormate(rawData.SQFileSize)
+      types.push({ type: 'flac', size, hash: rawData.SQFileHash })
+      _types.flac = {
+        size,
+        hash: rawData.SQFileHash,
+      }
+    }
+    if (rawData.ResFileSize !== 0) {
+      let size = sizeFormate(rawData.ResFileSize)
+      types.push({ type: 'flac24bit', size, hash: rawData.ResFileHash })
+      _types.flac24bit = {
+        size,
+        hash: rawData.ResFileHash,
+      }
+    }
+    return {
+      singer: decodeName(formatSingerName(rawData.Singers, 'name')),
+      name: decodeName(rawData.SongName),
+      albumName: decodeName(rawData.AlbumName),
+      albumId: rawData.AlbumID,
+      songmid: rawData.Audioid,
+      source: 'kg',
+      interval: formatPlayTime(rawData.Duration),
+      _interval: rawData.Duration,
+      img: null,
+      lrc: null,
+      otherSource: null,
+      hash: rawData.FileHash,
+      types,
+      _types,
+      typeUrl: {},
+    }
+  },
+  handleResult(rawData) {
+    let ids = new Set()
+    const list: any[] = []
+    rawData.forEach(item => {
+      const key = item.Audioid + item.FileHash
+      if (ids.has(key)) return
+      ids.add(key)
+      list.push(this.filterData(item))
+      for (const childItem of item.Grp) {
+        const key = item.Audioid + item.FileHash
+        if (ids.has(key)) continue
+        ids.add(key)
+        list.push(this.filterData(childItem))
+      }
+    })
+    return list
+  },
+  search(str, page = 1, limit, retryNum = 0) {
+    if (++retryNum > 3) return Promise.reject(new Error('try max num'))
+    if (limit == null) limit = this.limit
+    // http://newlyric.kuwo.cn/newlyric.lrc?62355680
+    return this.musicSearch(str, page, limit).then(result => {
+      if (!result || result.error_code !== 0) return this.search(str, page, limit, retryNum)
+      let list = this.handleResult(result.data.lists)
+
+      if (list == null) return this.search(str, page, limit, retryNum)
+
+      this.total = result.data.total
+      this.page = page
+      this.allPage = Math.ceil(this.total / limit)
+
+      return Promise.resolve({
+        list,
+        allPage: this.allPage,
+        limit,
+        total: this.total,
+        source: 'kg',
+      })
+    })
+  },
+}