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/index.ts

@@ -0,0 +1,42 @@
+import leaderboard from './leaderboard.ts'
+import { apis } from '../api-source.ts'
+import songList from './songList.ts'
+import musicSearch from './musicSearch.ts'
+import pic from './pic.ts'
+import lyric from './lyric.ts'
+import hotSearch from './hotSearch.ts'
+import comment from './comment.ts'
+import singer from './singer.ts'
+import album from './album.ts'
+// import tipSearch from './tipSearch.ts'
+
+const kg = {
+  // tipSearch,
+  leaderboard,
+  songList,
+  musicSearch,
+  hotSearch,
+  comment,
+  singer,
+  album,
+  getMusicUrl(songInfo, type) {
+    return apis('kg').getMusicUrl!(songInfo, type)
+  },
+  getLyric(songInfo) {
+    return lyric.getLyric(songInfo)
+  },
+  // getLyric(songInfo) {
+  //   return apis('kg').getLyric(songInfo)
+  // },
+  getPic(songInfo) {
+    return pic.getPic(songInfo)
+  },
+  getMusicDetailPageUrl(songInfo) {
+    return `https://www.kugou.com/song/#hash=${songInfo.hash}&album_id=${songInfo.albumId}`
+  },
+  // getPic(songInfo) {
+  //   return apis('kg').getPic(songInfo)
+  // },
+}
+
+export default kg