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/utils/user-agent-info.ts

@@ -0,0 +1,71 @@
+export interface UserAgentInfo {
+  browser: string | null
+  operatingSystem: string | null
+  device: string | null
+}
+
+const BROWSER_PATTERNS: Array<[RegExp, string]> = [
+  [/Edg\//i, 'Microsoft Edge'],
+  [/OPR\//i, 'Opera'],
+  [/Chrome\//i, 'Chrome'],
+  [/Safari\//i, 'Safari'],
+  [/Firefox\//i, 'Firefox'],
+  [/MSIE |Trident\//i, 'Internet Explorer']
+]
+
+const OS_PATTERNS: Array<[RegExp, string]> = [
+  [/Windows NT 10\.0/i, 'Windows 10/11'],
+  [/Windows NT 6\.3/i, 'Windows 8.1'],
+  [/Windows NT 6\.2/i, 'Windows 8'],
+  [/Windows NT 6\.1/i, 'Windows 7'],
+  [/Windows/i, 'Windows'],
+  [/Mac OS X ([\d_.]+)/i, 'macOS'],
+  [/iPhone OS ([\d_]+)/i, 'iOS'],
+  [/iPad.*CPU OS ([\d_]+)/i, 'iPadOS'],
+  [/Android ([\d.]+)/i, 'Android'],
+  [/Linux/i, 'Linux']
+]
+
+const DEVICE_PATTERNS: Array<[RegExp, string]> = [
+  [/iPhone/i, 'iPhone'],
+  [/iPad/i, 'iPad'],
+  [/Android.*Mobile/i, 'Android Phone'],
+  [/Android/i, 'Android Tablet'],
+  [/Windows Phone/i, 'Windows Phone'],
+  [/Macintosh/i, 'Mac'],
+  [/Windows/i, 'Windows PC'],
+  [/Linux/i, 'Linux PC']
+]
+
+export function parseUserAgent(userAgent: string | null | undefined): UserAgentInfo {
+  const ua = (userAgent ?? '').trim()
+  if (!ua) return { browser: null, operatingSystem: null, device: null }
+
+  let browser: string | null = null
+  for (const [regex, name] of BROWSER_PATTERNS) {
+    if (regex.test(ua)) {
+      browser = name
+      break
+    }
+  }
+
+  let operatingSystem: string | null = null
+  for (const [regex, name] of OS_PATTERNS) {
+    if (regex.test(ua)) {
+      operatingSystem = name
+      break
+    }
+  }
+
+  let device: string | null = null
+  for (const [regex, name] of DEVICE_PATTERNS) {
+    if (regex.test(ua)) {
+      device = name
+      break
+    }
+  }
+
+  return { browser, operatingSystem, device }
+}
+
+export type LoginMethod = 'password' | 'oauth' | 'webauthn' | 'totp_2fa' | 'email_2fa'