probe(physics): ACDREAM_PROBE_STEP_HEIGHTS — three readings along #338's chain

The live reading of 0.400 says the controller held its default at that
instant, not why. Two very different causes produce it: the
Setup-derived prepare/publish path never runs for the local player, or
it runs and a later writer clobbers the result. Fixing without knowing
which is a coin flip.

One reading at each hop — prepare (Setup value computed and scaled),
publish (assigned to the controller), resolve (what the resolver is
actually handed) — with a decision table on the flag mapping each
pattern to its cause, including the 0.000 case that would mean a null
Setup took the retail dummy path.

Edge-triggered per site, so the per-tick resolve site prints once per
distinct pair and cannot drown the two one-shot sites it exists to be
compared against. Prepare prints the raw authored pair beside the
scaled one, so a surprise separates wrong-Setup from wrong-scale
without a second run.

Lives in PhysicsDiagnostics per code-structure rule 5 rather than as
per-call-site env reads. Zero cost when off.

Suite 11,231 passed / 4 skipped / 0 failed.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/AcDream.Runtime/Gameplay/PlayerMovementController.cs

@@ -2625,6 +2625,15 @@ public sealed class PlayerMovementController
             // or it re-zeros the gravity velocity and the body re-wedges instead of falling off.
             bool candidateMoved = postIntegratePos != preIntegratePos;
 
+            // #338 (TEMPORARY): third and last reading along the chain — what
+            // the resolver is ACTUALLY handed, per ordinary movement tick.
+            // Edge-triggered inside the probe, so this per-tick site prints
+            // once per distinct pair and cannot drown the two one-shot sites
+            // it exists to be compared against.
+            PhysicsDiagnostics.LogStepHeights(
+                "resolve", StepUpHeight, StepDownHeight,
+                $"onWalkable={_body.OnWalkable} cell=0x{CellId:X8}");
+
             // ── 3. Collision resolution via CTransition sphere-sweep ─────────────
             // The Transition system subdivides the movement from pre→post into
             // sphere-radius steps, testing terrain collision at each step.