refactor(api)!: 平台 id 回退——joox/5sing/bili/apple 恢复全名，目录对齐 bd/mg

- 撤销 3381e9b/1b972ec 中 jx/5s/bl/ap 四个短码，恢复 joox/5sing/bili/apple；
  qian→bd、migu→mg 保留
- 目录与文件对齐保留的新 id：sdk/qian/→sdk/bd/、sdk/migu/→sdk/mg/、
  sdk/apis/qian.ts→bd.ts、migu.ts→mg.ts、src/http/migu-stream.ts→mg-stream.ts
  （规则改为「目录=对外 id」，聚合入口的模块变量同步更名；music.migu.cn 等域名、
  上游 music-lib 对照注释、miguGet 等功能标识符不动）
- 对外 id 全表：kw kg tx wy qs xm me qt lr mg bd joox 5sing bili apple

**破坏性变更**：joox/5sing/bili/apple 四平台的 URL、/sources 返回与
data/auth.json 凭据键恢复全名，已存短码键的登录态需重新登录。

验证：typecheck ✓、pnpm test 112/112 ✓

sdk/joox/album.ts

@@ -40,7 +40,7 @@ const fetchAlbumTracks = async(albumId: string, page: number, limit: number) =>
 
   const total = firstNonZero(body?.tracks?.total_count, body?.tracks?.list_count, list.length)
   return {
-    source: 'jx' as const,
+    source: 'joox' as const,
     info: {
       name: String(firstNonEmpty(body?.name, albumId)),
       img: pickJooxImage(body?.images) || null,
@@ -95,7 +95,7 @@ export const getAlbumDetailFromPage = async(rawId: string, page = 1, limit = 50)
 
   const total = firstNonZero(albumData?.trackList?.total_count, albumData?.trackList?.list_count, items.length)
   return {
-    source: 'jx' as const,
+    source: 'joox' as const,
     info: {
       name: String(firstNonEmpty(albumData?.title, albumId)),
       img: cover || null,
@@ -120,7 +120,7 @@ export const searchAlbum = async(keyword: string, page = 1, limit = 20) => {
   const url = `${SEARCH_URL}?country=sg&lang=zh_cn&keyword=${encodeURIComponent(String(keyword ?? ''))}`
   const { statusCode, body } = await httpFetch(url, { headers: jooxHeaders(), timeout: 20000 }).promise as any
   if (statusCode != 200 || !body?.section_list) {
-    return { list: [], total: 0, page, limit, source: 'jx' as const }
+    return { list: [], total: 0, page, limit, source: 'joox' as const }
   }
 
   const list: any[] = []
@@ -142,12 +142,12 @@ export const searchAlbum = async(keyword: string, page = 1, limit = 20) => {
         publishDate: String(album.publish_date ?? '').trim(),
         trackCount: 0,
         link: jooxAlbumLink(id),
-        source: 'jx' as const,
+        source: 'joox' as const,
       })
     }
   }
 
-  return { list: list.slice(0, limit), total: list.length, page, limit, source: 'jx' as const }
+  return { list: list.slice(0, limit), total: list.length, page, limit, source: 'joox' as const }
 }
 
 /** 专辑链接解析（上游 ParseAlbum） */