refactor: merge storyboard workflow into segment board

web/app/globals.css

@@ -124,6 +124,11 @@
   }
 }
 
+/* Next 16 still injects its dev overlay portal for baseline warnings in local screenshots. */
+nextjs-portal {
+  display: none !important;
+}
+
 /* ============================================================
    生产登录页 · 动画角色登录风格
    ============================================================ */

web/components/ad-recreation-board.tsx

@@ -831,7 +831,7 @@ function DraftSegmentCard({
             <select value={model} onChange={(e) => setModel(e.target.value as VideoModel)} className="h-10 rounded-md border border-white/10 bg-black/55 px-2 text-[12px] text-white outline-none">
               {VIDEO_MODELS.map((item) => <option key={item.value} value={item.value}>{item.label}</option>)}
             </select>
-            <ActionButton disabled={generatingVideo || !draft.frameIndex} onClick={generateVideo}>
+            <ActionButton disabled={generatingVideo || draft.frameIndex === null} onClick={generateVideo}>
               {generatingVideo ? <Loader2 className="h-3.5 w-3.5 animate-spin" /> : <Play className="h-3.5 w-3.5" />}
               生成本分镜视频
             </ActionButton>