@

feat(web): 演出配置 Timeline 加「场景底图」选择器(venue 特写)

- 后端 /api/sceneshots：列 SceneShots 全部俯视底图(venue 特写) name->{url,bounds}
- timeline.js：底图优先级 ir.stage.backdrop(venue) > 点位集默认 shot；
  顶栏加底图下拉 renderMapInfo + applyBackdrop(换底+改投影范围+重画+回调)
- app.js：拉 /api/sceneshots；performSelect 传入；saveBackdrop 写 ir.stage.backdrop 并 PUT
- venue 特写与点位集同 map-local → 换底图后锚点自动落对位(无头实拍擂台验证)
- ir.stage.backdrop 是编辑器元数据：validate 不读、compile 不碰
@

web/static/app.js

@@ -3,6 +3,7 @@
   const App = {
     dict: { conditions: {}, grants: {} },
     pointsets: {},        // name -> {mapId, points:[]}
+    sceneshots: {},       // name -> {url,bounds,w,h}（演出配置「场景底图」可选项）
     events: [],
     current: null,        // 当前 group
     ir: null,             // 工作副本
@@ -42,6 +43,7 @@
     try {
       App.dict = await (await api("/api/dictionary")).json();
       App.pointsets = await (await api("/api/pointsets")).json();
+      try { App.sceneshots = await (await api("/api/sceneshots")).json(); } catch (_) { App.sceneshots = {}; }
     } catch (e) { return; }
     await loadList();
   }
@@ -252,12 +254,27 @@
       host.appendChild(d);
     });
   }
+  let performIr = null;   // 演出配置当前事件 IR（底图选择写这里并持久化）
   async function performSelect(group) {
     let d;
     try { d = await (await api("/api/events/" + encodeURIComponent(group))).json(); } catch (e) { return; }
     performCurrent = group;
+    performIr = d.ir;
     performLoadList();
-    Timeline.show($("perform-main"), d.ir, App.dict, App.pointsets);
+    Timeline.show($("perform-main"), d.ir, App.dict, App.pointsets, {
+      sceneshots: App.sceneshots,
+      onPickBackdrop: name => saveBackdrop(group, name),
+    });
+  }
+  // 演出配置选底图 → 写 ir.stage.backdrop（编辑器元数据，validate/compile 都不读）并 PUT 持久化。
+  async function saveBackdrop(group, name) {
+    if (!performIr || group !== performCurrent) return;
+    performIr.stage = performIr.stage || {};
+    if (name) performIr.stage.backdrop = name; else delete performIr.stage.backdrop;
+    try {
+      await api("/api/events/" + encodeURIComponent(group), { method: "PUT", body: JSON.stringify({ ir: performIr, by: App.by }) });
+      toast(name ? ("底图已设为 " + name) : "已恢复默认底图");
+    } catch (e) { toast("底图保存失败"); }
   }
 
   // ---------- 导入 ----------