feat(songs): 歌曲管理支持批量驳回、投稿留言自动审查与排期范围可见性过滤

- 新增 /api/admin/songs/batch-reject.post 批量驳回接口（事务清排期/投票/扣接纳数/黑名单去重/异步通知）
- requireSongAdmin 三角色校验 + createApiError 统一错误包装
- scheduleDaysBefore/After 四字段排期可见范围限制（开放 API 与公开排期接口三处缓存路径 + DB 条件过滤）
- submissionNoteAutoModeration 基于黑名单 KEYWORD/LANGUAGE/GENRE 自动判定留言 publicStatus，命中自动关闭 submissionNotePublic
- 更新 songs/request.post 与 songs/[id]/update.put 接入自动审查逻辑

server/config/constants.ts

@@ -180,3 +180,13 @@ export const RISK_CONTROL_CONSTANTS = {
   SONG_IP_DOMINANCE_PERCENT: 0.6,
   SONG_IP_MIN_SAMPLE: 8
 } as const
+
+export const SERVER_ERROR_CODES = {
+  AUTH_UNAUTHORIZED: 'AUTH_UNAUTHORIZED',
+  AUTH_FORBIDDEN: 'AUTH_FORBIDDEN',
+  SONG_NOT_FOUND: 'SONG_NOT_FOUND',
+  SONG_OPERATION_FAILED: 'SONG_OPERATION_FAILED',
+  SONG_BATCH_REJECT_IDS_REQUIRED: 'SONG_BATCH_REJECT_IDS_REQUIRED',
+  SONG_BATCH_REJECT_LIMIT_EXCEEDED: 'SONG_BATCH_REJECT_LIMIT_EXCEEDED',
+  SONG_BATCH_REJECT_REASON_REQUIRED: 'SONG_BATCH_REJECT_REASON_REQUIRED'
+} as const