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

app/composables/useSiteConfig.js

@@ -19,7 +19,9 @@ const siteConfig = ref({
   siteVersion: '',
   submissionGuidelines: '',
   icpNumber: '',
-  gonganNumber: ''
+  gonganNumber: '',
+  defaultTheme: null,
+  enabledThemes: null
 })
 
 const isLoaded = ref(false)
@@ -57,7 +59,9 @@ export const useSiteConfig = () => {
         gonganNumber: '',
         enableReplayRequests: false,
         enableCollaborativeSubmission: true,
-        enableSubmissionRemarks: false
+        enableSubmissionRemarks: false,
+        defaultTheme: 'System',
+        enabledThemes: '["System","ClassicDark","ClassicLight","ModernLight"]'
       }
       isLoaded.value = true
     } finally {
@@ -96,6 +100,32 @@ export const useSiteConfig = () => {
   const enableSubmissionRemarks = computed(() => siteConfig.value.enableSubmissionRemarks === true)
   const smtpEnabled = computed(() => !!siteConfig.value.smtpEnabled)
 
+  function parseEnabledThemes(raw) {
+    if (Array.isArray(raw)) return raw.filter(Boolean)
+    if (typeof raw === 'string') {
+      const s = raw.trim()
+      if (!s) return []
+      if (s.startsWith('[') || s.startsWith('{')) {
+        try {
+          const parsed = JSON.parse(s)
+          if (Array.isArray(parsed)) return parsed.filter(Boolean)
+          if (parsed && Array.isArray(parsed.items)) return parsed.items.filter(Boolean)
+        } catch (_) {
+          // fallback to comma split
+        }
+      }
+      return s.split(',').map((x) => x.trim()).filter(Boolean)
+    }
+    return []
+  }
+
+  const defaultTheme = computed(() =>
+    typeof siteConfig.value.defaultTheme === 'string' && siteConfig.value.defaultTheme
+      ? siteConfig.value.defaultTheme
+      : null
+  )
+  const enabledThemes = computed(() => parseEnabledThemes(siteConfig.value.enabledThemes))
+
   // 初始化配置（仅在客户端执行）
   const initSiteConfig = async () => {
     if (typeof window !== 'undefined' && !isLoaded.value) {
@@ -126,6 +156,8 @@ export const useSiteConfig = () => {
     enableCollaborativeSubmission,
     enableSubmissionRemarks,
     smtpEnabled,
+    defaultTheme,
+    enabledThemes,
     fetchSiteConfig,
     initSiteConfig,
     refreshSiteConfig