feat(agent): 云端 Agent 运行时 - 完善 Pi 桥接、上下文压力与临时故障重试

backend/internal/app/cloud_agent.go

@@ -494,10 +494,6 @@ func (s *Service) CreateCloudAgentRun(userID string, req CloudAgentRequest, pare
 		canonical.Messages = append(append([]map[string]any{}, canonical.Messages[:len(canonical.Messages)-1]...), catalog, last)
 	}
 	s.attachCloudAgentLessons(&canonical, userID, req.Prompt)
-	// 必须登记进 state.Policy（值拷贝）：state 才是随任务持久化、被运行期读取的那份，
-	// 在这里改局部 policy 不会生效。登记之后压力读数的"系统提示分段"才能把 memory 摊开，
-	// 并与 system 桶合计对齐。
-	cloudAgentRecordMemorySegment(&state.Policy, canonical.SystemPrompt)
 	canonical.PromptCacheKey = cloudAgentPromptCacheKeyForRequest(req.CanvasID, cloudAgentPromptCacheIdentity(req, policy), canonical.SystemPrompt, canonical.Tools)
 	attachCloudAgentPlan(&canonical, inheritedPlan)
 	input := map[string]any{"mode": "text", "prompt": req.Prompt, "textHistory": history, "textOptions": map[string]any{"stream": true, "thinking": cloudAgentReasoningEnabled(policy.ReasoningMode)}, "cloudAgent": state,