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/useTheme.ts

@@ -1,4 +1,4 @@
-import { computed, ref, watch } from 'vue'
+import { computed, ref, watch, nextTick } from 'vue'
 
 const STORAGE_KEY = 'voicehub:theme'
 type ThemeName = string & {}
@@ -15,6 +15,25 @@ function getMetaThemeColor() {
   return document.querySelector<HTMLMetaElement>('meta[name="theme-color"]')
 }
 
+function parseEnabledThemesRaw(raw: unknown): string[] {
+  if (Array.isArray(raw)) return raw.filter(Boolean) as string[]
+  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) as string[]
+        if (parsed && Array.isArray((parsed as any).items)) return (parsed as any).items.filter(Boolean) as string[]
+      } catch (_) {
+        // fallback
+      }
+    }
+    return s.split(',').map((x) => x.trim()).filter(Boolean)
+  }
+  return []
+}
+
 function applyTheme(theme: string) {
   if (!isBrowser()) return
 
@@ -24,11 +43,12 @@ function applyTheme(theme: string) {
   root.setAttribute('data-theme', theme)
   if (appRoot) appRoot.setAttribute('data-theme', theme)
 
-  if (theme === 'dark') {
+  const effective = resolveEffectiveTheme(theme)
+  if (effective === 'dark') {
     root.classList.add('dark')
     root.classList.remove('light')
     root.style.colorScheme = 'dark'
-  } else if (theme === 'light') {
+  } else if (effective === 'light') {
     root.classList.add('light')
     root.classList.remove('dark')
     root.style.colorScheme = 'light'
@@ -39,11 +59,7 @@ function applyTheme(theme: string) {
 
   const meta = getMetaThemeColor()
   if (meta) {
-    if (theme === 'light') {
-      meta.content = '#f8fafc'
-    } else {
-      meta.content = '#111111'
-    }
+    meta.content = effective === 'light' ? '#f8fafc' : '#111111'
   }
 
   try {
@@ -59,18 +75,37 @@ function detectSystemTheme(): 'dark' | 'light' {
   return prefersDark ? 'dark' : 'light'
 }
 
+function resolveEffectiveTheme(theme: string): 'dark' | 'light' | string {
+  if (theme === 'System' || theme === 'system') {
+    return detectSystemTheme()
+  }
+  if (theme === 'dark' || theme.endsWith('Dark')) return 'dark'
+  if (theme === 'light' || theme.endsWith('Light')) return 'light'
+  return theme
+}
+
 export function useTheme() {
   const config = useRuntimeConfig()
+  const { isLoaded: siteConfigLoaded, defaultTheme: siteDefaultTheme, enabledThemes: siteEnabledThemes, initSiteConfig } = useSiteConfig()
 
   const enabledThemes = computed<string[]>(() => {
-    const list = (config.public?.enabledThemes as unknown) as string[] | undefined
-    return Array.isArray(list) && list.length > 0 ? list : ['dark', 'light']
+    if (siteConfigLoaded.value && siteEnabledThemes.value.length > 0) {
+      return [...new Set(siteEnabledThemes.value)]
+    }
+    const fromRuntime = parseEnabledThemesRaw(config.public?.enabledThemes)
+    if (fromRuntime.length > 0) return fromRuntime
+    return ['System', 'dark', 'light']
   })
 
   const defaultTheme = computed<string>(() => {
-    const value = config.public?.defaultTheme as string | undefined
-    if (value && enabledThemes.value.includes(value)) return value
-    return enabledThemes.value.includes('dark') ? 'dark' : enabledThemes.value[0] || 'dark'
+    if (siteConfigLoaded.value && siteDefaultTheme.value) {
+      return siteDefaultTheme.value
+    }
+    const fromRuntime = config.public?.defaultTheme
+    if (typeof fromRuntime === 'string' && fromRuntime) {
+      return fromRuntime
+    }
+    return 'System'
   })
 
   const theme = computed<string>({
@@ -79,21 +114,22 @@ export function useTheme() {
   })
 
   const isDark = computed(() => {
-    const t = theme.value
-    if (t === 'dark') return true
-    if (t === 'light') return false
-    return detectSystemTheme() === 'dark'
+    return resolveEffectiveTheme(theme.value) === 'dark'
   })
 
   function isThemeEnabled(name: string) {
     return enabledThemes.value.includes(name)
   }
 
+  function firstValidTheme(candidate: string): string {
+    const list = enabledThemes.value
+    if (list.includes(candidate)) return candidate
+    if (list.includes(defaultTheme.value)) return defaultTheme.value
+    return list[0] ?? 'System'
+  }
+
   function setTheme(next: string, { persist = true } = {}) {
-    let candidate = next
-    if (!enabledThemes.value.includes(candidate)) {
-      candidate = defaultTheme.value
-    }
+    const candidate = firstValidTheme(next)
 
     if (currentTheme.value === candidate && initialized.value) return
 
@@ -110,7 +146,7 @@ export function useTheme() {
   }
 
   function toggleTheme() {
-    const order = enabledThemes.value.length >= 2 ? enabledThemes.value : ['dark', 'light']
+    const order = enabledThemes.value.length >= 2 ? enabledThemes.value : ['System', 'dark', 'light']
     const current = theme.value
     const idx = order.indexOf(current)
     const next = order[(idx + 1) % order.length]
@@ -121,8 +157,31 @@ export function useTheme() {
     setTheme(defaultTheme.value, { persist: false })
   }
 
-  function init() {
+  function onSystemThemeChange() {
+    const stored = (() => {
+      try {
+        return localStorage.getItem(STORAGE_KEY)
+      } catch {
+        return null
+      }
+    })()
+    if (!stored) {
+      applyTheme(theme.value)
+    }
+  }
+
+  async function init() {
     if (initialized.value || !isBrowser()) return
+
+    if (!siteConfigLoaded.value) {
+      try {
+        await initSiteConfig()
+        await nextTick()
+      } catch (_) {
+        /* ignore */
+      }
+    }
+
     initialized.value = true
 
     let stored: string | null = null
@@ -132,34 +191,43 @@ export function useTheme() {
       stored = null
     }
 
-    if (stored && enabledThemes.value.includes(stored)) {
-      setTheme(stored)
-      return
+    if (stored) {
+      const valid = firstValidTheme(stored)
+      if (valid === stored || enabledThemes.value.includes(stored)) {
+        setTheme(stored)
+        watchSystemTheme()
+        return
+      }
     }
 
     setTheme(defaultTheme.value, { persist: false })
+    watchSystemTheme()
+  }
 
-    if (window.matchMedia) {
-      const mql = window.matchMedia('(prefers-color-scheme: dark)')
-      const onChange = () => {
-        let s: string | null = null
-        try {
-          s = localStorage.getItem(STORAGE_KEY)
-        } catch {
-          s = null
-        }
-        if (!s) {
-          setTheme(defaultTheme.value, { persist: false })
-        }
-      }
-      if (typeof mql.addEventListener === 'function') {
-        mql.addEventListener('change', onChange)
-      } else if (typeof mql.addListener === 'function') {
-        mql.addListener(onChange)
-      }
+  function watchSystemTheme() {
+    if (!isBrowser() || !window.matchMedia) return
+    const mql = window.matchMedia('(prefers-color-scheme: dark)')
+    if (typeof mql.addEventListener === 'function') {
+      mql.addEventListener('change', onSystemThemeChange)
+    } else if (typeof (mql as any).addListener === 'function') {
+      ;(mql as any).addListener(onSystemThemeChange)
     }
   }
 
+  watch(defaultTheme, () => {
+    if (!initialized.value) return
+    const stored = (() => {
+      try {
+        return localStorage.getItem(STORAGE_KEY)
+      } catch {
+        return null
+      }
+    })()
+    if (!stored) {
+      setTheme(defaultTheme.value, { persist: false })
+    }
+  })
+
   return {
     theme,
     currentTheme,