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/api/site-config.get.ts

@@ -26,7 +26,13 @@ const publicFields = [
   'enableSubmissionRemarks',
   'enableRequestTimeLimitation',
   'forceBlockAllRequests',
-  'smtpEnabled'
+  'smtpEnabled',
+  'defaultTheme',
+  'enabledThemes',
+  'scheduleDaysBeforeEnabled',
+  'scheduleDaysBefore',
+  'scheduleDaysAfterEnabled',
+  'scheduleDaysAfter'
 ]
 
 const filterPublicSettings = (data: any) => {
@@ -81,7 +87,13 @@ export default defineEventHandler(async (event) => {
           enableRequestTimeLimitation: false,
           forceBlockAllRequests: false,
           enableReplayRequests: false,
-          smtpEnabled: false
+          smtpEnabled: false,
+          defaultTheme: 'System',
+          enabledThemes: '["System","ClassicDark","ClassicLight","ModernLight"]',
+          scheduleDaysBeforeEnabled: false,
+          scheduleDaysBefore: 30,
+          scheduleDaysAfterEnabled: false,
+          scheduleDaysAfter: 14
         })
         .returning()