fix: complete retail parity stability pass

tests/AcDream.App.Tests/Physics/LiveEntityNetworkOnPositionCollapseMatrixTests.cs

@@ -219,7 +219,7 @@ public sealed class LiveEntityNetworkOnPositionCollapseMatrixTests
     // ── Scenario 2: landing packet (the preserved rows 2a/2b asymmetry) ─
 
     [Fact]
-    public void LandingPacket_PlayerGuid_QueueClearedNoShadowPublish_316Preserved()
+    public void LandingPacket_PlayerGuid_QueueClearedAndShadowPublished()
     {
         using var fixture = new Fixture(PlayerGuid);
         EntityPhysicsHost host = fixture.InstallHost();
@@ -253,14 +253,13 @@ public sealed class LiveEntityNetworkOnPositionCollapseMatrixTests
         // Row 2a, PRESERVED for player guids: the interp queue IS cleared.
         Assert.False(fixture.Remote.Interp.IsActive);
 
-        // Row 2b / #316, PRESERVED (NOT fixed): the shadow is NOT
-        // republished for a player-guid landing — it stays at whatever it
-        // was before this packet.
+        // #316: the same resolved landing pose must publish to collision in
+        // this packet, not wait for a later physics tick to self-heal.
         ShadowEntry shadowEntry = Assert.Single(
             fixture.Shadows.AllEntriesForDebug(),
             entry => entry.EntityId == fixture.Entity.Id);
-        Assert.Equal(spawnShadowPos, shadowEntry.Position);
-        Assert.NotEqual(landingPos, shadowEntry.Position);
+        Assert.Equal(landingPos, shadowEntry.Position);
+        Assert.NotEqual(spawnShadowPos, shadowEntry.Position);
 
         // AP-135's cell-adopt bookkeeping still ran (via the post-routing
         // wire-cell adopt, not suppressed for AirborneSnap).
@@ -574,6 +573,26 @@ public sealed class LiveEntityNetworkOnPositionCollapseMatrixTests
         _ = host;
     }
 
+    [Fact]
+    public void PositionPackVelocity_DoesNotOverwriteAuthoritativeBodyVelocity()
+    {
+        using var fixture = new Fixture(CreatureGuid);
+        Vector3 authoritativeVectorUpdate = new(4f, 5f, 6f);
+        fixture.Remote.Body.Velocity = authoritativeVectorUpdate;
+
+        // Retail's airborne/non-teleport Position arm performs no placement,
+        // isolating the PositionPack velocity rule from contact resolution.
+        fixture.Controller.OnPosition(fixture.Update(
+            new Vector3(12f, 14f, SpawnHeight + 2f),
+            SourceCell,
+            teleportSequence: 1,
+            guid: CreatureGuid,
+            isGrounded: false,
+            velocity: new Vector3(0.7f, 0.2f, -0.1f)));
+
+        Assert.Equal(authoritativeVectorUpdate, fixture.Remote.Body.Velocity);
+    }
+
     // ── Sabotage check (contract §5, one-time, manual) ──────────────────
     //
     // Performed by hand during implementation, not committed as a test (a