feat(web): include removed in visible stats; cover bang badge

站内展示/统计统一 VISIBLE（含 removed）：热度、UP 列表、总览
active_ups/初导入计数、说明页粉丝覆盖、黑名单视频数。采集队列仍
只 active/unfaved。失效片封面右上角感叹号徽标，点击/tap 提示
「该视频已失效」；手动/候选入库仍可复活 removed→active。

reaction_board/web/static/views/video.js

@@ -1,6 +1,7 @@
 import { api } from "../api.js";
 import {
   badge, centerActiveChips, cover, emptyState, metricChips, metricGrid,
+  removedCoverMark,
   sectionHeader, videoCard,
 } from "../components.js";
 import { lineChart, themeColor } from "../charts.js";
@@ -53,7 +54,10 @@ export async function renderVideo(root, { params, query }) {
     </header>
 
     <div class="detail-hero">
-      ${cover(detail, "hero-cover")}
+      <div class="detail-cover-wrap">
+        ${cover(detail, "hero-cover")}
+        ${removedCoverMark(detail)}
+      </div>
       <div class="detail-hero-body">
         <h1>${escapeHtml(detail.title)}</h1>
         <div class="detail-meta">