feat(perform): 演出配置页(模式切换) + 镜头可视框始终可见

P1 反馈两处修改：
- 顶部加「海选审核 / 演出配置」模式切换；演出配置=独立页，左列仅已确认事件，
  选中即内嵌白模预览(弃用原弹窗)，为 P2 在此配置演出细节打底
- 修镜头框只在 dialogue 显式带 camera 时才画的 bug：改为镜头可视区域框始终可见，
  显式镜头点优先→跟随说话人→跟玩家→场景中心，框尺寸按世界单位随舞台缩放+焦点十字
- timeline.js 从弹窗固定ID重构为挂载到任意容器 Timeline.show(host,...);
  离线模型测试复跑两样张全过，重构未破坏逻辑

web/static/app.js

@@ -9,6 +9,7 @@
     status: null,
     selectedNode: null,
     dirty: false,
+    mode: "review",       // review=海选审核 / perform=演出配置
     by: localStorage.getItem("story_by") || "匿名",
   };
   window.App = App;
@@ -80,7 +81,7 @@
     App.current = group; App.ir = JSON.parse(JSON.stringify(d.ir));
     App.status = d.status; App.selectedNode = null; App.dirty = false;
     $("graph-empty").style.display = "none";
-    ["btn-save", "btn-validate", "btn-playtest", "btn-timeline", "btn-confirm", "btn-discard", "btn-addnode", "btn-autolayout", "btn-addsucc"].forEach(b => $(b).disabled = false);
+    ["btn-save", "btn-validate", "btn-playtest", "btn-confirm", "btn-discard", "btn-addnode", "btn-autolayout", "btn-addsucc"].forEach(b => $(b).disabled = false);
     renderAll(true);
     GraphUI.focusStart(App.ir);     // 定位到开头节点
     snapReset();                    // 初始化撤销栈
@@ -194,8 +195,42 @@
   // ---------- 试走 ----------
   $("btn-playtest").onclick = () => Playtest.open(App.ir, App.dict);
 
-  // ---------- 演出预览（白模时间线）----------
-  $("btn-timeline").onclick = () => Timeline.open(App.ir, App.dict, App.pointsets);
+  // ---------- 模式切换：海选审核 / 演出配置 ----------
+  function setMode(m) {
+    App.mode = m;
+    $("mode-review").classList.toggle("active", m === "review");
+    $("mode-perform").classList.toggle("active", m === "perform");
+    $("wrap").classList.toggle("hidden", m !== "review");
+    $("perform-wrap").classList.toggle("hidden", m !== "perform");
+    $("review-toolbar").style.display = m === "review" ? "" : "none";
+    Timeline.stop();
+    if (m === "perform") performLoadList();
+  }
+  $("mode-review").onclick = () => setMode("review");
+  $("mode-perform").onclick = () => setMode("perform");
+
+  // ---------- 演出配置页：已确认事件列表 + 内嵌白模预览 ----------
+  let performCurrent = null;
+  async function performLoadList() {
+    let list;
+    try { list = await (await api("/api/events?status=confirmed")).json(); } catch (e) { return; }
+    const host = $("perform-list"); host.innerHTML = "";
+    if (!list.length) { host.innerHTML = '<div class="empty" style="padding:14px">还没有已确认的事件。去「海选审核」确认事件后再来配置演出。</div>'; return; }
+    list.forEach(e => {
+      const d = document.createElement("div");
+      d.className = "ev" + (e.group === performCurrent ? " sel" : "");
+      d.innerHTML = '<div class="t">' + esc(e.title || e.group) + '</div><div class="g">' + esc(e.group) + ' · ' + esc(e.updated_by || "") + '</div>';
+      d.onclick = () => performSelect(e.group);
+      host.appendChild(d);
+    });
+  }
+  async function performSelect(group) {
+    let d;
+    try { d = await (await api("/api/events/" + encodeURIComponent(group))).json(); } catch (e) { return; }
+    performCurrent = group;
+    performLoadList();
+    Timeline.show($("perform-main"), d.ir, App.dict, App.pointsets);
+  }
 
   // ---------- 导入 ----------
   let importFiles = [];   // 当前已选文件