feat(timeline): 交互式分支演出 + 从任意节点开始 + 时间轴分面板/自适应

- 交互分支：播到选择/战斗/随机节点暂停，在镜头下方弹按钮手选，点完接对应分支续演
- 从任意节点开始：单击节点选中→「从选中处开始」或双击节点，立即从该处播放；
  起始位置按从开头到该节点途中的走位重放算出(角色站在应有位置)，已离线验证
- 布局分两块(上舞台/下时间轴)，时间轴 playhead 仅播放时居中、暂停可自由滚
- 时间轴自适应宽度按钮(整条压进可视区)+鼠标滚轮横向滚动，解决长时间轴够不着节点
- 演示事件 QY_TLDEMO 扩充两条分支(和解→随机夜晚/拔剑→战斗胜败)，去掉对焦NP1

samples/timeline_demo.ir.json

@@ -1,7 +1,7 @@
 {
   "id": "QY_TLDEMO",
   "title": "演出预览功能演示",
-  "theme": "P1 白模演出测试（走位/对话打字机/动画/镜头/多角色）",
+  "theme": "P1 白模演出测试（走位/对话/动画/镜头/选择/随机/战斗）",
   "scale": "演示",
   "roles": [
     { "slot": "NP1", "name": "神秘剑客", "archetype": "负伤外门高手", "camp": 0 },
@@ -13,18 +13,48 @@
     { "id": "n_p1walk", "kind": "move", "actor": "P1", "to": "PT_DOOR", "next": "n_p1say" },
     { "id": "n_p1say", "kind": "dialogue", "speaker": "P1", "text": "（这客栈看着冷清，却处处透着古怪……）", "next": "n_npenter" },
     { "id": "n_npenter", "kind": "move", "actor": "NP1", "to": "PT_CENTER", "next": "n_npsay" },
-    { "id": "n_npsay", "kind": "dialogue", "speaker": "NP1", "camera": "NP1", "text": "阁下，留步。在下身负旧伤，想借贵宝地歇一晚，天明即走。", "next": "n_draw" },
+    { "id": "n_npsay", "kind": "dialogue", "speaker": "NP1", "text": "阁下，留步。在下身负旧伤，想借贵宝地歇一晚，天明即走。", "next": "n_draw" },
     { "id": "n_draw", "kind": "anim", "actor": "NP1", "ani": "draw_sword", "next": "n_p1ask" },
     { "id": "n_p1ask", "kind": "dialogue", "speaker": "P1", "text": "来者何人？这般夜半叩门，又突然按剑，意欲何为？", "next": "n_xiaoer" },
     { "id": "n_xiaoer", "kind": "move", "actor": "NP2", "to": "PT_SIDE", "next": "n_xsay" },
     { "id": "n_xsay", "kind": "dialogue", "speaker": "NP2", "text": "二位客官息怒！有话好好说，小店实在经不起折腾啊……", "next": "n_choice" },
+
     { "id": "n_choice", "kind": "choice", "options": [
-      { "text": "收剑，请他进来歇脚", "goto": "end_peace" },
-      { "text": "拔剑相向，喝令他离开", "goto": "end_fight" }
-    ] }
+      { "text": "收剑，请他进来歇脚", "goto": "sc_peace1" },
+      { "text": "拔剑相向，喝令他离开", "goto": "sc_fight1" }
+    ] },
+
+    { "id": "sc_peace1", "kind": "dialogue", "speaker": "P1", "text": "（罢了，他确实带着伤，眼神也不像歹人。）", "next": "sc_peace2" },
+    { "id": "sc_peace2", "kind": "anim", "actor": "P1", "ani": "sheath_sword", "next": "sc_peace3" },
+    { "id": "sc_peace3", "kind": "dialogue", "speaker": "NP1", "text": "多谢。萍水相逢，承蒙阁下不弃，这份情，在下记下了。", "next": "sc_peace4" },
+    { "id": "sc_peace4", "kind": "move", "actor": "NP2", "to": "PT_CENTER", "next": "sc_peace5" },
+    { "id": "sc_peace5", "kind": "dialogue", "speaker": "NP2", "text": "好嘞！二位里边请，小的这就去沏一壶热茶，再添两副碗筷！", "next": "sc_peace6" },
+    { "id": "sc_peace6", "kind": "move", "actor": "NP1", "to": "PT_SIDE", "next": "sc_peace_rand" },
+    { "id": "sc_peace_rand", "kind": "random", "branches": [
+      { "weight": 60, "goto": "sc_peace_calm" },
+      { "weight": 40, "goto": "sc_peace_night" }
+    ] },
+    { "id": "sc_peace_calm", "kind": "narration", "speaker": "P1", "text": "这一夜风停雨歇，客栈里难得安宁。剑客和衣而眠，天没亮便悄然上路。", "next": "sc_peace_calm2" },
+    { "id": "sc_peace_calm2", "kind": "dialogue", "speaker": "NP1", "text": "后会有期。他日江湖再见，必当厚报。", "next": "end_peace" },
+    { "id": "sc_peace_night", "kind": "narration", "speaker": "P1", "text": "三更天，窗外忽有黑影一闪而过。剑客猛然睁眼，按住了腰间的剑。", "next": "sc_peace_night2" },
+    { "id": "sc_peace_night2", "kind": "move", "actor": "NP1", "to": "PT_DOOR", "next": "sc_peace_night3" },
+    { "id": "sc_peace_night3", "kind": "dialogue", "speaker": "NP1", "text": "阁下，麻烦没完——他们找上门了。今夜怕是要承你一把剑。", "next": "end_peace_twist" },
+
+    { "id": "sc_fight1", "kind": "dialogue", "speaker": "P1", "text": "想进这道门，先问过我手里的剑！", "next": "sc_fight2" },
+    { "id": "sc_fight2", "kind": "anim", "actor": "P1", "ani": "draw_sword", "next": "sc_fight3" },
+    { "id": "sc_fight3", "kind": "dialogue", "speaker": "NP1", "text": "既然阁下不肯通融……那就别怪在下。得罪了！", "next": "sc_fight4" },
+    { "id": "sc_fight4", "kind": "move", "actor": "NP1", "to": "PT_DOOR", "next": "sc_fight_battle" },
+    { "id": "sc_fight_battle", "kind": "fight", "fight_type": 1, "camp2": [ "NP1" ], "win": "sc_fight_win", "lose": "sc_fight_lose" },
+    { "id": "sc_fight_win", "kind": "dialogue", "speaker": "P1", "text": "承让。你伤成这样还要硬闯，又是何苦。", "next": "sc_fight_win2" },
+    { "id": "sc_fight_win2", "kind": "move", "actor": "NP1", "to": "PT_SIDE", "next": "sc_fight_win3" },
+    { "id": "sc_fight_win3", "kind": "dialogue", "speaker": "NP1", "text": "好剑法……是在下唐突了。告辞。", "next": "end_fight_win" },
+    { "id": "sc_fight_lose", "kind": "dialogue", "speaker": "NP1", "text": "阁下手下留情。这一晚的账，日后江湖上再算。", "next": "sc_fight_lose2" },
+    { "id": "sc_fight_lose2", "kind": "move", "actor": "NP1", "to": "PT_CENTER", "next": "end_fight_lose" }
   ],
   "endings": [
-    { "id": "end_peace", "summary": "化干戈为玉帛，与剑客结为知己", "grants": [], "result": "success" },
-    { "id": "end_fight", "summary": "不欢而散，剑客消失在茫茫雨夜中", "grants": [], "result": "end" }
+    { "id": "end_peace", "summary": "结义同盟，平安一夜", "grants": [], "result": "success" },
+    { "id": "end_peace_twist", "summary": "夜半生变，新的麻烦找上门", "grants": [], "result": "end" },
+    { "id": "end_fight_win", "summary": "技高一筹，剑客败退消失在雨夜", "grants": [], "result": "success" },
+    { "id": "end_fight_lose", "summary": "技不如人，被剑客闯入客栈", "grants": [], "result": "fail" }
   ]
 }