diff --git a/src/AcDream.App/Composition/SessionPlayerComposition.cs b/src/AcDream.App/Composition/SessionPlayerComposition.cs
index cd6ae920..d7ae0328 100644
--- a/src/AcDream.App/Composition/SessionPlayerComposition.cs
+++ b/src/AcDream.App/Composition/SessionPlayerComposition.cs
@@ -354,6 +354,14 @@ internal sealed class SessionPlayerCompositionPhase
         // every other reveal condition (streaming residence, spawn-cell
         // readiness, terrain residence, quiescence) is unchanged.
         WbDrawDispatcher? revealDispatcher = live.DrawDispatcher;
+        // #262 (Campaign P P6): the #111 [snap] apparatus was designed as a
+        // permanent low-volume diagnostic (one line per login/teleport entry
+        // snap) but PhysicsEngine.DiagnosticLog was never wired in production,
+        // so the 2026-07-29 Coldeve acceptance log was structurally silent on
+        // which Resolve branch the run-on-the-spot login took. Wire it per
+        // session composition (a session reset constructs a fresh engine).
+        d.PhysicsEngine.DiagnosticLog =
+            static line => System.Console.WriteLine(line);
         var revealRenderResources = new WorldRevealRenderResourceScheduler(
             foundation.MeshAdapter is { } revealMeshes
                 ? revealMeshes.SetDestinationRevealUploadPriority