feat(pointview): 新增「场景/点位」页签——正交俯视真实场景底图 + 点位精确叠加

第三个页签(与海选审核/演出配置平级)，只读查看每个点位集里各点的真实
位置/朝向，配 move.to/camera.focus 时对照用，不必回 Unity 翻 json。

- pointview.js: 独立白模点位查看器(按 kind 上色/朝向箭头/悬停坐标/侧栏清单)；
  有底图则把正交俯视真实场景图当画布底图、点位按 shot.bounds 线性投上去
  (像素级对齐家具)，带显隐开关；无底图回退黑底白模。
- app.py: /api/pointsets 给有底图的点位集附 shot{url,bounds}；新增
  /sceneshot/{name}.png 路由(防目录穿越)。
- Dockerfile/compose: 加 STORY_SCENESHOTS_DIR(/sceneshots) env + 挂载点与注释。

底图由 SGame 仓新增 Editor 工具「剧情场景俯视抓拍」产出
({name}.png + {name}.shot.json，map-local 覆盖范围)。

web/static/app.js

@@ -9,7 +9,7 @@
     status: null,
     selectedNode: null,
     dirty: false,
-    mode: "review",       // review=海选审核 / perform=演出配置
+    mode: "review",       // review=海选审核 / perform=演出配置 / points=场景点位
     by: localStorage.getItem("story_by") || "匿名",
   };
   window.App = App;
@@ -196,20 +196,50 @@
   // ---------- 试走 ----------
   $("btn-playtest").onclick = () => Playtest.open(App.ir, App.dict);
 
-  // ---------- 模式切换：海选审核 / 演出配置 ----------
+  // ---------- 模式切换：海选审核 / 演出配置 / 场景点位 ----------
   function setMode(m) {
     App.mode = m;
     $("mode-review").classList.toggle("active", m === "review");
     $("mode-perform").classList.toggle("active", m === "perform");
+    $("mode-points").classList.toggle("active", m === "points");
     $("wrap").classList.toggle("hidden", m !== "review");
     $("perform-wrap").classList.toggle("hidden", m !== "perform");
+    $("points-wrap").classList.toggle("hidden", m !== "points");
     $("review-toolbar").style.display = m === "review" ? "" : "none";
     document.body.classList.toggle("perform-mode", m === "perform");   // 切背景色调
+    document.body.classList.toggle("points-mode", m === "points");
     Timeline.stop();
+    if (m === "points") PointView.clear();
     if (m === "perform") performLoadList();
+    if (m === "points") pointsLoadList();
   }
   $("mode-review").onclick = () => setMode("review");
   $("mode-perform").onclick = () => setMode("perform");
+  $("mode-points").onclick = () => setMode("points");
+
+  // ---------- 场景点位页：点位集列表 + 只读白模查看器 ----------
+  let pointsCurrent = null;
+  function pointsLoadList() {
+    const names = Object.keys(App.pointsets || {}).sort();
+    const host = $("points-set-list"); host.innerHTML = "";
+    if (!names.length) { host.innerHTML = '<div class="empty" style="padding:14px">未找到任何点位集（StreamingAssets/Story/PointSets/*.points.json）。</div>'; return; }
+    names.forEach(name => {
+      const ps = App.pointsets[name] || {};
+      const cnt = (ps.anchors || ps.points || []).length;
+      const d = document.createElement("div");
+      d.className = "ev" + (name === pointsCurrent ? " sel" : "");
+      d.innerHTML = '<div class="t">' + esc(name) + '</div><div class="g">'
+        + (ps.mapId ? '地图 ' + esc(ps.mapId) + ' · ' : '') + cnt + ' 个点</div>';
+      d.onclick = () => pointsSelect(name);
+      host.appendChild(d);
+    });
+  }
+  function pointsSelect(name) {
+    pointsCurrent = name;
+    pointsLoadList();
+    $("points-empty").style.display = "none";
+    PointView.show($("points-view"), name, App.pointsets[name] || {});
+  }
 
   // ---------- 演出配置页：已确认事件列表 + 内嵌白模预览 ----------
   let performCurrent = null;