fix(api): create_plan接口增加asset_ids参数并传递给PlanGeneratorService

- EditPlanCreateRequest增加asset_ids字段
- create_plan调用generate_from_template时传递body.asset_ids而非硬编码空数组
- asset_ids同时写入plan.config，供generate时兜底分配
- 新增test_create_with_asset_ids测试验证参数传递

apps/api/app/api/routes/edit_plans.py

@@ -50,6 +50,7 @@ class EditPlanCreateRequest(BaseModel):
     config: dict[str, Any] = Field(default_factory=dict, description="计划配置 (JSON)")
     total_duration: float = Field(default=0.0, ge=0.0, description="总时长 (秒)")
     project_id: str = Field(default="", description="所属项目 ID")
+    asset_ids: List[str] = Field(default_factory=list, description="素材 ID 列表，创建时自动分配给片段")
 
 
 class EditPlanUpdateRequest(BaseModel):
@@ -419,7 +420,7 @@ def create_plan(
         result = generator.generate_from_template(
             template=template,
             clip_configs=clip_configs,
-            asset_ids=[],
+            asset_ids=body.asset_ids,
             project_id=project_id,
             created_by_user_id=current_user.user.id,
             name=body.name,
@@ -445,6 +446,13 @@ def create_plan(
             total_duration=body.total_duration if body.total_duration > 0 else None,
         )
 
+    # 把 asset_ids 写入 plan.config，供生成时兜底分配使用
+    if body.asset_ids:
+        current_config = plan.config or {}
+        if current_config.get("asset_ids") != body.asset_ids:
+            current_config["asset_ids"] = body.asset_ids
+            plan = svc.update_plan(plan.id, config=normalize_plan_config(current_config))
+
     logger.info(
         "创建剪辑计划: id=%s name=%s clips=%d by user=%s",
         plan.id,