feat(web): home media sections use 5-up PC / 1-up mobile grid, growth top5

reaction_board/web/static/views/home.js

@@ -15,9 +15,9 @@ function statChip(label, value, { href = null, tone = "" } = {}) {
   return `<div class="live-chip ${tone}">${inner}</div>`;
 }
 
-function heatStrip(items) {
+function heatGrid(items) {
   if (!items.length) return emptyState("暂无热度数据", "完成一次快照后这里会出现榜单。");
-  return `<div class="heat-strip">
+  return `<div class="media-grid">
     ${items.map((item, index) => mediaCard(item, {
       rank: index + 1,
       meta: `${escapeHtml(item.up_name || "未知 UP")} · ${formatCount(item.metrics?.view)} 播放`,
@@ -65,7 +65,7 @@ export async function renderHome(root) {
     api("/api/overview"),
     api("/api/videos", { sort: "published", within_days: 14, limit: 5 }),
     api("/api/videos", { sort: "heat", limit: 5 }),
-    api("/api/videos", { sort: "growth", growth_days: 7, limit: 3 }),
+    api("/api/videos", { sort: "growth", growth_days: 7, limit: 5 }),
   ]);
 
   const pending = overview.counts.candidates_pending || 0;
@@ -112,7 +112,7 @@ export async function renderHome(root) {
         <a class="text-link" href="/videos?sort=published&within_days=30">查看全部</a>
       </div>
       <p class="section-note">按视频发布时间排序，与入库时间无关。</p>
-      <div class="video-list">
+      <div class="media-grid">
         ${published.items.length ? published.items.map((item) => publishedCard(item)).join("")
           : emptyState("最近 14 天没有新发布视频", "搜索发现的新视频会逐步补充。")}
       </div>
@@ -124,7 +124,7 @@ export async function renderHome(root) {
         <a class="text-link" href="/videos?sort=growth&growth_days=7">增长榜</a>
       </div>
       ${growth.available && growth.items.length
-        ? `<div class="video-list">${growth.items.map((item, index) => growthCard(item, index)).join("")}</div>`
+        ? `<div class="media-grid">${growth.items.map((item, index) => growthCard(item, index)).join("")}</div>`
         : emptyState("需要至少 2 天快照", growth.reason || "当前只有 1 个数据点，明天开始显示播放增量。")}
     </section>
 
@@ -133,7 +133,7 @@ export async function renderHome(root) {
         <h2>热度速览</h2>
         <a class="text-link" href="/videos?sort=heat">完整榜单</a>
       </div>
-      ${heatStrip(heat.items)}
+      ${heatGrid(heat.items)}
     </section>
 
     ${capacity(overview.folders || [])}