feat: 角色重跑参考当前立绘+提示词,保持人物一致 (row42)

原「重跑」立绘是纯文生图,每次重抽成另一个随机人。改为:角色已有当前立绘时,
重跑传该立绘作参考图 → 后端走 image_edit(参考立绘+提示词),保持同一人物相貌/发型/身份一致。

- generate_base_asset 新增 reference_asset_id;person 有参考图则 image_edit + build_person_portrait_prompt_refs
- run_base_asset_task image_edit size 按 kind 区分(person 立绘竖 1024x1536,商品三视图横)
- 全链路透传 reference_asset_id:pipeline.regenPortrait(传 viewPortraitAsset)→ genBaseAsset →
  onGenerateBaseAsset → api.generateBaseAsset → generate-base-asset 端点
场景重跑不受影响(仍文生图);需部署生效(后端)。

构建: tsc=0/build=0; py_compile OK; projects+assets 测试无新增回归(基线 4 fail 2 err)。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

core/backend/apps/projects/views.py

@@ -487,7 +487,7 @@ class ProjectViewSet(TeamScopedViewSetMixin, ModelViewSet):
         if kind not in BaseAssetGroup.Kind.values:
             return Response({"detail": "invalid base asset kind"}, status=status.HTTP_400_BAD_REQUEST)
         try:
-            task = generate_base_asset(project=project, user=request.user, kind=kind, prompt=request.data.get("prompt", ""), label=request.data.get("label", ""))
+            task = generate_base_asset(project=project, user=request.user, kind=kind, prompt=request.data.get("prompt", ""), label=request.data.get("label", ""), reference_asset_id=request.data.get("reference_asset_id") or None)
         except ValueError as exc:  # 无可用模型 / 余额不足等,立即反馈
             return Response({"detail": str(exc)}, status=status.HTTP_400_BAD_REQUEST)
         stage, _ = ProjectStage.objects.get_or_create(project=project, stage=ProjectStage.Stage.BASE_ASSETS)