fix: pipeline_id为空时fallback到默认产线，修复产线slash匹配不到

pipeline_service/agent_loop_v2.py

@@ -333,6 +333,14 @@ class AgentExecutor:
             except Exception:
                 pass
 
+        # pipeline_id 为空时 fallback 到默认产线（保证 slash/ability/skill 统一按产线挂载）
+        if not self.pipeline_id:
+            try:
+                from pipeline_core import DEFAULT_ABILITY_ID
+                self.pipeline_id = DEFAULT_ABILITY_ID
+            except ImportError:
+                pass
+
     async def _build_system_prompt(self, user_input: str) -> str:
         """组装完整 system prompt = 基础 prompt + 记忆 + 技能 + 工具列表"""
         prompt = self.config.system_prompt