修复导出问题

src/views/Stage.vue

@@ -222,7 +222,6 @@ function bakeSystemFrames(system: ParticleSystem, emitter: ParticleEmitter, fps:
 function ensureFramesBaked(fps: number) {
   const totalFrames = Math.max(2, Math.floor(store.timeline.totalFrames) || 2)
   const subEmitterIds = collectSubEmitterIds(store.systems)
-  let complete = true
   // 烘焙预热会大量出生/死亡粒子，期间暂停跨系统事件，避免注入预热粒子。
   emitterSync.suspendEvents(true)
   try {
@@ -231,13 +230,16 @@ function ensureFramesBaked(fps: number) {
       if (subEmitterIds.has(system.id)) continue
       if ((system.frames?.length || 0) >= totalFrames) continue
       const emitter = emitterSync.emitters.get(system.id)
-      if (!emitter) { complete = false; continue }
+      if (!emitter) continue
       bakeSystemFrames(system as unknown as ParticleSystem, emitter, fps, totalFrames)
     }
   } finally {
     emitterSync.suspendEvents(false)
   }
-  if (complete) store.timeline.recorded = true
+  // 子发射器必须通过父事件逐帧录制；只补齐根系统时不能把整段烘焙标记为完成。
+  if (store.systems.every((system) => (system.frames?.length || 0) >= totalFrames)) {
+    store.timeline.recorded = true
+  }
 }
 
 function loop() {