M1：镜生域后端闭环——灵胚/照心试演/启镜原子闸门/执镜关系/命台租约/魂籍签名导出/死亡冷静期（迁移 001，测试 7 用例）

backend/app/schemas/runtime.py

@@ -66,11 +66,17 @@ class RunResponse(BaseModel):
     )
 
     id: str = Field(description="运行 ID，前缀为 run_。")
-    character_id: str = Field(description="所属人物 ID。")
-    session_id: str | None = Field(description="关联会话 ID。")
+    character_id: str | None = Field(
+        default=None, description="所属人物 ID；照心试演（kind=rehearsal）无正式人物。"
+    )
+    session_id: str | None = Field(default=None, description="关联会话 ID。")
     status: str = Field(
         description="运行状态：queued / running / completed / failed / cancelled / interrupted。"
     )
+    kind: str = Field(
+        default="foreground",
+        description="运行种类：foreground / background_task / awakening / rehearsal（契约词典 §8.2）。",
+    )
     goal: str | None = Field(description="运行目标。")
     origin: str = Field(description="运行来源，例如 chat。")
     model_hint: str | None = Field(description="本次运行使用的逻辑模型名或能力槽位。")