feat(growth): same-day 1-day baselines for new videos

Let 1-day view growth use a zero baseline for videos published today, and the first successful sample for older videos ingested today, without mixing those into 7/30-day rankings.

reaction_board/web/static/views/about.js

@@ -92,7 +92,7 @@ export async function renderAbout(root) {
         <li>B 站不公开完播率与单 P 播放，内容小时是“供给时长”，不是“实际观看时长”。</li>
         <li>多 P 可能让同一用户产生多次播放计数，本站不单独校正，属于已知偏差。</li>
         <li>粉丝数可能包含不活跃账号；粉丝快照暂不参与任何榜单。</li>
-        <li>样本不足（少于 2 天快照、单视频 UP）会显示提示，不伪造 0。</li>
+        <li>近 7/30 日增长仍要跨日快照。近 1 日：当日发布按 0 起算；更早发布的新入库按入库时播放量起算，需当天至少两次采样。样本不足时显示提示，不伪造 0。</li>
       </ul>
     </section>
 

reaction_board/web/static/views/home.js

@@ -69,7 +69,7 @@ export async function renderHome(root) {
   const growthEmptyTitle = growth.reason
     || `近 ${growthDays} 日增长暂不可用`;
   const growthEmptyHint = growthDays <= 1
-    ? "当前快照不足，完成至少 2 天快照后即可显示播放增量。"
+    ? "当日发布按 0 起算；更早发布的新入库需要当天至少两次采样。"
     : `需要至少 ${growthDays + 1} 天快照才能计算近 ${growthDays} 日增长。`;
   const updatedLabel = formatClock(overview.updated_at);
   const dataDateLabel = formatDataDate(overview.data_date);

reaction_board/web/static/views/rankings.js

@@ -179,6 +179,12 @@ function durationNote(data) {
   return `<div class="section-note">内容效率与互动效率：时长 ≥ ${filter.min_duration_seconds} 秒、发布满 ${filter.maturity_days} 天、播放 ≥ ${filter.min_view}${shrink}；时长缺失不参与。</div>`;
 }
 
+function growthNote(sort, growthDays) {
+  if (sort !== "growth" && sort !== "growth_rate") return "";
+  if (Number(growthDays) !== 1) return "";
+  return `<div class="section-note">近 1 日：当日发布按 0 起算；更早发布的新入库按入库时播放量起算，需要当天至少两次采样。</div>`;
+}
+
 function bindControls(root) {
   root.querySelector("#rank-sort")?.addEventListener("change", (event) => {
     replaceQuery({ sort: event.target.value, page: null });
@@ -245,6 +251,7 @@ async function renderScope(root, { query }, scope) {
     </header>
     ${controls({ scope, sort, within, year, growthDays, q, years })}
     ${durationNote(data)}
+    ${growthNote(sort, growthDays)}
     ${data.available === false ? `<div class="notice-row warning">
       <strong>${sort.startsWith("growth") ? "增长数据尚不可用" : "榜单筛选后为空"}</strong>
       <span>${escapeHtml(data.reason || "")}</span>

reaction_board/web/static/views/video.js

@@ -62,7 +62,7 @@ export async function renderVideo(root, { params, query }) {
           <span>${escapeHtml(formatDuration(detail.duration))}</span>
           ${detail.pages ? `<span>${formatNumber(detail.pages)} P</span>` : ""}
           ${badge(statusLabel(detail.status), `status-${detail.status}`)}
-          ${samples < 2 ? badge("样本不足", "warning") : ""}
+          ${samples < 2 && !detail.growth?.available ? badge("样本不足", "warning") : ""}
         </div>
         ${detail.blacklisted ? `<p class="section-note warning-text">该 UP 在黑名单中；黑名单只影响未来发现，不影响当前视频追踪。</p>` : ""}
         ${detail.up_follower_backfilled ? `<p class="section-note">UP 粉丝数为回填值，不是真实的入库时点。</p>` : ""}