Version: 0.9.61.dev.260501

后端：
1. 主动调度 graph + session bridge 收口——把 dry-run / select / preview / confirm / rerun 串成受限 graph，新增 active_schedule_sessions 缓存与聊天拦截，ready_preview 后释放回自由聊天
2. 会话与通知链路对齐——notification 统一绑定 conversation_id，action_url 指向 /assistant/{conversation_id}，会话不存在改回 404 语义，避免 wrong param type 误导排障
3. estimated_sections 写入与主动调度消费链路补齐——任务创建、quick task 与随口记入口都透传估计节数，主动调度只消费落库值

前端：
4. AssistantPanel 最小适配主动调度预览与失败态——复用主动调度卡片/微调弹窗，补历史加载失败可见提示与跨账号会话拦截

文档：
5. 更新主动调度缺口分阶段实施计划和实现方案，标记阶段 0-2 收口并同步接力状态

backend/active_scheduler/preview/converter.go

@@ -174,7 +174,7 @@ func entryFromEvent(event ports.ScheduleEventFact) SchedulePreviewEntry {
 	return entry
 }
 
-func riskDTO(selected candidate.Candidate, observation observe.Result, changes []ActiveScheduleChangeItem) RiskDTO {
+func riskDTO(selected candidate.Candidate, observation observe.Result, changes []ActiveScheduleChangeItem, fallbackUsed bool) RiskDTO {
 	affectedIDs := make([]int, 0)
 	seen := make(map[int]bool)
 	for _, change := range changes {
@@ -198,7 +198,7 @@ func riskDTO(selected candidate.Candidate, observation observe.Result, changes [
 		RiskMetrics:  observation.Metrics.Risk,
 		AffectedIDs:  affectedIDs,
 		RequiresLLM:  observation.Decision.LLMSelectionRequired,
-		FallbackUsed: observation.Decision.FallbackCandidateID == selected.CandidateID,
+		FallbackUsed: fallbackUsed,
 	}
 }