feat(m4b): 增加可追踪谣言传播与回放

[变更性质]
- 本提交新增 M4b 谣言传播与确定性验收能力，不是单纯缺陷修复。

[新增功能]
- 支持带来源、父节点、深度、强度和路径的谣言传播、去重、衰减与过期处理。
- Headless 支持稳定谣言 dump、replay，以及与 batch 模式的互斥校验。

[实现方案]
- 通过不可变 World 更新和失败原子返回保持模拟确定性。
- 新增多跳传播、重复转述、过期父节点、非法参与者和稳定 trace 测试。

[影响范围]
- 影响 Kernel、Headless 和 Kernel 测试；不包含 M5/M6 或无关配置与文档改动。

1 files changed, 4 insertions, 2 deletions

diff --git a/src/LivingVillage.Kernel.Tests/RelationTests.fs b/src/LivingVillage.Kernel.Tests/RelationTests.fs
index dc433a7..20331ce 100644
--- a/src/LivingVillage.Kernel.Tests/RelationTests.fs
+++ b/src/LivingVillage.Kernel.Tests/RelationTests.fs
@@ -35,7 +35,8 @@ module RelationHarness =
           Avatar = { Pos = { X = 0.0f; Y = 0.0f } }
           NoHost = { Reserved = 0UL }
           Npcs = [| mkNpc 0 mem0; mkNpc 1 mem1 |]
-          Events = [] }
+          Events = []
+          Rumors = [] }
 
     let chatted (tick: int64) (partner: int) : MemoryEvent =
         { Tick = tick; Kind = Chatted(NpcId partner); Valence = Sim.chatValence }
@@ -184,7 +185,8 @@ type RelationTests () =
               Avatar = { Pos = plaza }
               NoHost = { Reserved = 0UL }
               Npcs = [| self; nearest; alternate |]
-              Events = [] }
+              Events = []
+              Rumors = [] }
         let next = Sim.step RelationHarness.zeroInput world
         match List.tryHead next.Npcs.[0].Mind.Memory with
         | Some entry ->