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。

2 files changed, 50 insertions, 0 deletions

diff --git a/src/LivingVillage.Kernel.Tests/DeterminismTests.fs b/src/LivingVillage.Kernel.Tests/DeterminismTests.fs
index 52cae89..c4b4154 100644
--- a/src/LivingVillage.Kernel.Tests/DeterminismTests.fs
+++ b/src/LivingVillage.Kernel.Tests/DeterminismTests.fs
@@ -113,6 +113,30 @@ type DeterminismTests () =
             checkedTicks <- checkedTicks + 1
         Assert.IsTrue(120001 = checkedTicks)
 
+    /// P23：512x384 参数化边界下，avatar 与全部 NPC 在长跑中仍留在 [0, max] 且数值有限。
+    [<TestMethod>]
+    member _.LargeMapBoundsClampAvatarAndNpcs () =
+        Sim.configureBounds 512 384
+        try
+            let trace = DriverHarness.run 4242UL 20000L
+            let maxX = float32 (Sim.mapWidthTiles * Sim.tilePixels - Sim.tilePixels)
+            let maxY = float32 (Sim.mapHeightTiles * Sim.tilePixels - Sim.tilePixels)
+            Assert.IsTrue(maxX > 64.0f * float32 Sim.tilePixels, "512 map must extend past legacy width")
+            for w in trace do
+                let p = w.Avatar.Pos
+                if Single.IsNaN p.X || Single.IsNaN p.Y then Assert.Fail($"NaN avatar at tick {w.Tick}")
+                if p.X < 0.0f || p.X > maxX then Assert.Fail($"avatar X out of bounds at tick {w.Tick}: {p.X}")
+                if p.Y < 0.0f || p.Y > maxY then Assert.Fail($"avatar Y out of bounds at tick {w.Tick}: {p.Y}")
+                for npc in w.Npcs do
+                    if Single.IsNaN npc.Pos.X || Single.IsNaN npc.Pos.Y then
+                        Assert.Fail($"NaN npc {npc.Id} at tick {w.Tick}")
+                    if npc.Pos.X < 0.0f || npc.Pos.X > maxX then
+                        Assert.Fail($"npc {npc.Id} X out of bounds at tick {w.Tick}: {npc.Pos.X}")
+                    if npc.Pos.Y < 0.0f || npc.Pos.Y > maxY then
+                        Assert.Fail($"npc {npc.Id} Y out of bounds at tick {w.Tick}: {npc.Pos.Y}")
+        finally
+            Sim.configureBounds 64 48
+
     [<TestMethod>]
     member _.SplitMix64MatchesKnownVectors () =
         let expected : uint64 list =
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