feat: home growth auto(7→1) and hourly recent-video snapshot

- Add analytics.home_growth_days (auto|1|7); API growth_days=auto tries 7 then 1
- Homepage shows active window and growth-board link; clearer empty reason
- New snapshot_recent scheduler task (schedule.recent_snapshot_minutes/days)
- run_recent_videos refreshes new aids only; never touches completed/backup
- Full 00:01 job keeps ok=1 skip (covers hourly refresh within 1h); mutex with recent

reaction_board/web/static/views/system.js

@@ -38,6 +38,7 @@ export async function renderSystem(root) {
   const health = system.snapshot_health || { total: 0, ok: 0, failed: 0 };
   const counts = system.counts || {};
   const next = system.next_runs || {};
+  const running = system.running || {};
 
   const visitExtra = visitStats
     ? `<span class="section-note">近 ${visitStats.days} 天 · ${visitStats.pending ? "含未落库缓冲" : "已落库"}</span>`
@@ -92,12 +93,13 @@ export async function renderSystem(root) {
 
     <section class="panel">
       ${sectionHeader("预计下次运行")}
-      <div class="status-grid status-row-3">
+      <div class="status-grid status-row-4">
         <div><span>咻咻满粉丝数更新</span><strong>${running.fans ? "运行中" : escapeHtml(formatDateTime(next.fans))}</strong></div>
         <div><span>视频数据快照 + UP 信息</span><strong>${running.snapshot ? "运行中" : escapeHtml(formatDateTime(next.snapshot))}</strong></div>
+        <div><span>新视频小时同步</span><strong>${running.snapshot_recent ? "运行中" : escapeHtml(formatDateTime(next.snapshot_recent))}</strong></div>
         <div><span>新视频搜索</span><strong>${running.discover || running.discovery ? "运行中" : escapeHtml(formatDateTime(next.discover))}</strong></div>
       </div>
-      <p class="section-note">进行中显示「运行中」；空闲时按该任务上次完成时间推算下次运行，不按墙钟抢跑。</p>
+      <p class="section-note">进行中显示「运行中」；空闲时按该任务上次完成时间推算下次运行，不按墙钟抢跑。新视频小时同步与全站快照互斥。</p>
     </section>
 
     <section class="panel">