diff --git a/AGENTS.md b/AGENTS.md
index eee16e9..fc0fd56 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -93,6 +93,8 @@
 - 生成代码前必须先参考 `AGENTS.md`、当前项目后端规范和既有代码习惯；遇到类职责或目录归属不确定时，先询问再继续，不能先写完再统一重构。
 - 不写魔法值，稳定业务代码使用常量或枚举。
 - 集合、空值、字符串、时间、金额和 `BigDecimal` 使用安全写法。
+- 后端业务时间点统一按 UTC 处理：数据库 `LocalDateTime` 默认表示 UTC，API 返回时间点字段必须使用带 `Z` 的 ISO 8601 UTC 时间；新增响应 DTO 优先使用 `OffsetDateTime`，从数据库快照输出时使用 `UtcTimeFormatter` 统一转换。
+- 入住日期、离店日期、酒店营业日等酒店本地业务日期不得和 UTC 时间点混用，应使用 `LocalDate` 或明确酒店时区语义的字段。
 - 异常不吞掉，日志有上下文但不输出 Secret 或个人敏感信息。
 - 写操作考虑幂等、并发版本、事务边界、审计和失败恢复。
 - 复杂业务规则、外部字段映射、脱敏和幂等逻辑必须有必要中文注释。
diff --git a/docs/project/backend-development-guidelines.md b/docs/project/backend-development-guidelines.md
index b122c93..3da8249 100644
--- a/docs/project/backend-development-guidelines.md
+++ b/docs/project/backend-development-guidelines.md
@@ -210,6 +210,7 @@ groupCode
 - 注释必须说明业务含义、来源或代码值范围。
 - 禁止使用“字段1”“备用字段”等模糊注释。
 - 业务时间点以 UTC 写入数据库，API 层负责返回带 `Z` 的 ISO 8601 UTC 时间，例如 `2026-07-08T03:00:00Z`。
+- 新增 API 响应 DTO 中的时间点字段优先使用 `OffsetDateTime`；从数据库 `LocalDateTime` 快照输出到接口时，应通过 `UtcTimeFormatter` 转换，禁止直接把无时区 `LocalDateTime` 暴露给前端或 SuperAgent。
 - 酒店本地业务日期，例如入住日期、离店日期、营业日，优先使用 `LocalDate` 或明确酒店时区语义的字段，不和 UTC 时间点混用。
 - JSON 字段只用于扩展元数据，不替代需要查询、约束或索引的正式列。
 
diff --git a/server/src/main/java/cn/nianxx/thhotel/workflows/reservation/service/impl/ReservationTaskAvailabilityResolver.java b/server/src/main/java/cn/nianxx/thhotel/workflows/reservation/service/impl/ReservationTaskAvailabilityResolver.java
index d148f4d..8049d8c 100644
--- a/server/src/main/java/cn/nianxx/thhotel/workflows/reservation/service/impl/ReservationTaskAvailabilityResolver.java
+++ b/server/src/main/java/cn/nianxx/thhotel/workflows/reservation/service/impl/ReservationTaskAvailabilityResolver.java
@@ -31,6 +31,9 @@ public class ReservationTaskAvailabilityResolver {
      * 计算任务可处理状态。FAILED 和 COMPLETED 视为前置任务结束，不阻塞后续任务。
      */
     public ReservationTaskAvailabilityResult calculateAvailability(ReservationTaskSnapshot task) {
+        if (!Boolean.TRUE.equals(task.queueParticipation())) {
+            return calculateAvailability(task, null);
+        }
         ReservationTaskSnapshot blockingTask = workflowRepository
                 .findQueueTasksBefore(task.hotelId(), task.orderId(), task.executionOrder())
                 .stream()
diff --git a/server/src/test/java/cn/nianxx/thhotel/workflows/reservation/service/impl/ReservationTaskAvailabilityResolverTest.java b/server/src/test/java/cn/nianxx/thhotel/workflows/reservation/service/impl/ReservationTaskAvailabilityResolverTest.java
new file mode 100644
index 0000000..502d257
--- /dev/null
+++ b/server/src/test/java/cn/nianxx/thhotel/workflows/reservation/service/impl/ReservationTaskAvailabilityResolverTest.java
@@ -0,0 +1,60 @@
+package cn.nianxx.thhotel.workflows.reservation.service.impl;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.anyLong;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.ArgumentMatchers.nullable;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import cn.nianxx.thhotel.workflows.reservation.common.dto.ReservationTaskSnapshot;
+import cn.nianxx.thhotel.workflows.reservation.common.enums.ReservationTaskStatus;
+import cn.nianxx.thhotel.workflows.reservation.common.result.ReservationTaskAvailabilityResult;
+import cn.nianxx.thhotel.workflows.reservation.repository.ReservationAiWorkflowRepository;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+class ReservationTaskAvailabilityResolverTest {
+
+    @Test
+    void shouldReturnReadOnlyForNonQueueTaskWithoutQueryingPreviousTasks() {
+        ReservationAiWorkflowRepository workflowRepository = mock(ReservationAiWorkflowRepository.class);
+        when(workflowRepository.findQueueTasksBefore(anyString(), anyLong(), nullable(Integer.class)))
+                .thenReturn(List.of());
+        ReservationTaskAvailabilityResolver resolver = new ReservationTaskAvailabilityResolver(workflowRepository);
+        ReservationTaskSnapshot nonQueueTask = task(false, null, ReservationTaskStatus.PENDING_CONFIRM.name());
+
+        ReservationTaskAvailabilityResult result = resolver.calculateAvailability(nonQueueTask);
+
+        assertThat(result.blocked()).isFalse();
+        assertThat(result.readOnly()).isTrue();
+        assertThat(result.editable()).isFalse();
+        assertThat(result.confirmable()).isFalse();
+        assertThat(result.executable()).isFalse();
+        verify(workflowRepository, never()).findQueueTasksBefore(anyString(), anyLong(), nullable(Integer.class));
+    }
+
+    private ReservationTaskSnapshot task(Boolean queueParticipation, Integer executionOrder, String taskStatus) {
+        return new ReservationTaskSnapshot(
+                930000000000001001L,
+                "HOTEL-TEST",
+                930000000000001101L,
+                930000000000001201L,
+                930000000000001301L,
+                "message_notification",
+                "Message Notification",
+                "MESSAGE_NOTIFICATION",
+                "MESSAGE_NOTIFICATION",
+                "message_notification",
+                taskStatus,
+                queueParticipation,
+                executionOrder,
+                null,
+                null,
+                null,
+                false,
+                null);
+    }
+}