test(kernel): 512x384 参数化边界存档 round-trip 与 NPC 边界回归（P23）

- Sim.configureBounds 512 384 下 v2 存档 round-trip 且同 world 两次保存逐字节一致，
  读回再保存仍与原文一致；v1 的 64x48 兼容由既有用例覆盖。
- DriverHarness 长跑 20000 tick 断言 avatar 与全部 NPC 有限且留在 [0,max] 内。
- Kernel 测试 90 -> 92。

1 files changed, 26 insertions, 0 deletions

diff --git a/src/LivingVillage.Kernel.Tests/M6aTests.fs b/src/LivingVillage.Kernel.Tests/M6aTests.fs
index 9348b0f..94341a1 100644
--- a/src/LivingVillage.Kernel.Tests/M6aTests.fs
+++ b/src/LivingVillage.Kernel.Tests/M6aTests.fs
@@ -314,3 +314,29 @@ type M6aTests () =
         finally
             Sim.configureBounds 64 48
             if File.Exists path then File.Delete path
+
+    /// P23：512x384 参数化边界在存档 v2 中 round-trip；同 world 两次保存逐字节一致，
+    /// 读回后再次保存仍与原文一致（v1 的 64x48 兼容由 SaveV1LegacyStillReadable 覆盖）。
+    [<TestMethod>]
+    member _.SaveRoundTrips512x384BoundsAndIsByteStable () =
+        let path = "p23-bounds-512-v2.save"
+        let path2 = path + ".2"
+        try
+            Sim.configureBounds 512 384
+            let world = Sim.initialWorld (uint64 4242)
+            WorldSave.saveToFile path world
+            WorldSave.saveToFile path2 world
+            let text = File.ReadAllText path
+            Assert.IsTrue(text.StartsWith("LV_WORLD_SAVE_V2"), "bounds save must stay v2")
+            Assert.AreEqual<string>(text, File.ReadAllText path2)
+            Sim.configureBounds 64 48
+            match WorldSave.loadFromFile path with
+            | Error failure -> Assert.Fail(sprintf "512x384 bounds save should load: %s" failure)
+            | Ok restored ->
+                Assert.AreEqual<int>(512, Sim.mapWidthTiles)
+                Assert.AreEqual<int>(384, Sim.mapHeightTiles)
+                Assert.AreEqual<string>(text, WorldSave.save restored)
+        finally
+            Sim.configureBounds 64 48
+            if File.Exists path then File.Delete path
+            if File.Exists path2 then File.Delete path2