feat(timeline): P1 白模演出预览——时间线+俯视舞台播放

- /api/pointsets 增 anchors(含 pos/rot/kind/npc 坐标)，保留 points 名字数组兼容下拉
- 新增 static/timeline.js：线性化主路径→按时长铺多轨时间线 + 2D 俯视白模舞台播放
  (走位插值/对话打字机/镜头俯视框示意/playhead/点击跳转)；战斗/选择/随机仅标点不模拟
- 工具栏加「演出预览」按钮 + 预览遮罩 + 暗金主题样式
- 时长模型：对话=字数×打字机速度，走位=坐标距离÷速度，动画/镜头给缺省时长
- node 离线测试两样张(含 out_ref+fight+skip)逻辑全过；修掉结局重复渲染 bug

设计文档见主仓 docs/plans/2026-06-13-story-timeline-editor-and-whitebox-preview-design.md (P1 期)

web/static/style.css

@@ -222,3 +222,36 @@ button.mini { padding:2px 8px; font-size:12px; }
 .pt-choices button { display:block; width:100%; text-align:left; margin:5px 0; }
 .pt-choices button.locked { opacity:.55; }
 .pt-q { color:#b89a5a; font-size:12px; margin:8px 0 4px; }
+
+/* ---- 演出预览（timeline + 白模舞台）---- */
+.modal.huge { width:840px; max-width:94vw; }
+.tl-mapinfo { font-size:12px; color:#9a8f7e; margin-left:12px; font-weight:normal; }
+#tl-stagewrap { background:#15130d; border:1px solid #3a322a; border-radius:6px; overflow:hidden; line-height:0; }
+#tl-stage { width:100%; height:auto; display:block; }
+#tl-controls { display:flex; align-items:center; gap:10px; margin:10px 0 6px; }
+#tl-controls .tip { font-size:11.5px; color:#7a7264; }
+.tl-time { font-size:13px; color:#e6c878; font-variant-numeric:tabular-nums; min-width:90px; }
+#tl-tracks { position:relative; overflow-x:auto; overflow-y:hidden; max-height:34vh;
+             background:#19150f; border:1px solid #3a322a; border-radius:6px; padding-top:20px; }
+.tl-ruler { position:relative; height:16px; border-bottom:1px solid #2a2419; }
+.tl-tick { position:absolute; top:0; height:16px; border-left:1px solid #2a2419; }
+.tl-tick span { font-size:9px; color:#6a6256; padding-left:3px; }
+.tl-lane { position:relative; border-bottom:1px solid #211c15; }
+.tl-lane-label { position:sticky; left:0; z-index:3; display:inline-block; min-width:54px;
+                 padding:2px 6px; font-size:11px; color:#b89a5a; background:#211c15;
+                 border-right:1px solid #2a2419; height:100%; box-sizing:border-box; line-height:26px; }
+.tl-clip { position:absolute; top:3px; height:22px; line-height:22px; padding:0 5px;
+           font-size:11px; color:#1a1710; border-radius:3px; overflow:hidden; white-space:nowrap;
+           text-overflow:ellipsis; cursor:pointer; box-sizing:border-box; box-shadow:0 1px 2px rgba(0,0,0,.4); }
+.tl-clip.active { outline:2px solid #fff; outline-offset:-1px; z-index:2; }
+.tl-clip.k-dialogue { background:#7ec8e3; }
+.tl-clip.k-move     { background:#e6c878; }
+.tl-clip.k-anim     { background:#9ee37e; }
+.tl-clip.k-camera   { background:#c89ee3; }
+.tl-clip.k-branch   { background:#9ec0f0; }
+.tl-clip.k-fight    { background:#e38f7e; }
+.tl-clip.k-reward   { background:#e0c060; }
+.tl-clip.k-ending   { background:#e0a850; }
+.tl-clip.k-stop     { background:#d87878; color:#fff; }
+.tl-playhead { position:absolute; top:0; bottom:0; width:2px; background:#ff5a4a;
+               pointer-events:none; z-index:4; box-shadow:0 0 4px rgba(255,90,74,.7); }