feat(schedule)+fix(schedule)+feat(player): 排期管理5项功能 - 紧凑布局/投稿人优先算法/localStorage持久化/备选池修复/播放队列按钮

* fix+style(schedule): ScheduleManager 标签页紧凑布局，头部 min-height 防抖，内容区统间距与移动端适配
* feat(schedule): 新增自动排期策略「按投稿人数优先覆盖」，按 requester+collaborators 数排序分配好时段
* feat(schedule): localStorage 键 voicehub:schedule:auto-config 持久化策略/时段/学期/过滤等7项，onMounted 恢复，watch debounce 500ms 保存
* fix(schedule): songs/index.get.ts 新增 use_pool 查询参数，备选池过滤条件 status=PENDING + song.played=false + song未在任何排期中；ScheduleManager/draft-bulk 创建排期时将池记录 UPDATE 为 ASSIGNED
* feat(player): ScheduleManager 工具栏新增「构建播放队列」按钮，按 playDate+playTimeId+sequence 排序后调用 useAudioPlayer.playSong 加载播放列表，支持 confirm 确认与 toast 反馈
* refactor(useSongs): fetchSongs 增加第5参数 usePool，透传 use_pool=true 到 /api/songs

server/api/songs/index.get.ts

@@ -8,9 +8,10 @@ import {
   songs,
   systemSettings,
   users,
-  votes
+  votes,
+  scheduleSongPool
 } from '~/drizzle/schema'
-import { and, asc, count, desc, eq, inArray, like, or } from 'drizzle-orm'
+import { and, asc, count, desc, eq, inArray, like, or, isNull, notInArray } from 'drizzle-orm'
 import { cacheService } from '~~/server/services/cacheService'
 import { formatDateTime } from '~/utils/timeUtils'
 import { maskSongsInfo, MaskableSong, MaskableUser } from '~~/server/utils/studentMask'
@@ -67,6 +68,7 @@ export default defineEventHandler(async (event) => {
     const sortBy = (query.sortBy as string) || 'createdAt'
     const sortOrder = (query.sortOrder as string) || 'desc'
     const bypassCache = query.bypass_cache === 'true'
+    const usePool = query.use_pool === 'true' || query.usePool === 'true'
 
     // 获取用户身份
     const user = event.context.user || null
@@ -203,6 +205,35 @@ export default defineEventHandler(async (event) => {
       conditions.push(eq(songs.requesterId, user.id))
     }
 
+    if (usePool) {
+      const poolRows = await db
+        .select({ songId: scheduleSongPool.songId })
+        .from(scheduleSongPool)
+        .where(
+          and(
+            eq(scheduleSongPool.status, 'PENDING'),
+            isNull(scheduleSongPool.targetPlayDate)
+          )
+        )
+        .groupBy(scheduleSongPool.songId)
+
+      const allScheduledSongIdsQuery = await db
+        .select({ songId: schedules.songId })
+        .from(schedules)
+
+      const scheduledIdsSet = new Set(allScheduledSongIdsQuery.map((r) => r.songId))
+      const candidateFromPool = new Set(
+        poolRows.map((r) => r.songId).filter((id) => !scheduledIdsSet.has(id))
+      )
+
+      if (candidateFromPool.size === 0) {
+        conditions.push(eq(songs.id, -1))
+      } else {
+        conditions.push(inArray(songs.id, Array.from(candidateFromPool)))
+      }
+      conditions.push(eq(songs.played, false))
+    }
+
     const whereCondition = conditions.length > 0 ? and(...conditions) : undefined
 
     // 查询歌曲总数