feat(diag): #266 - [stat-chain] apparatus across the vitae-to-movement chain

Three permanent low-volume probes: installed vitae record (id/type/key/
value) at ReplaceManifest, any vitae record dropped by GetMod's
spell-table prepass (retail's _vitae singleton never runs family
stacking - if this fires, hoist the Bucket-4 branch), and the full
recompute state (base skills, runMod, effective skills, active count).
One instrumented relog decides the break point.

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

src/AcDream.Runtime/Gameplay/RuntimeCharacterState.cs

@@ -183,6 +183,18 @@ public sealed class RuntimeCharacterState : IDisposable
         int jump = _jumpSkillBase >= 0
             ? ApplySkillEnchantments(_jumpSkillBase, JumpSkillId)
             : -1;
+        // #266 apparatus (permanent, low-volume — fires only on skill-base or
+        // enchantment changes, the [snap] class): the full stat-chain state at
+        // each recompute. If vitae is active but runMod prints 1.0, the break
+        // is in GetSkillMod's record handling; if runMod is right but the
+        // felt speed doesn't change, the break is downstream of MovementSkills.
+        EnchantmentMath.VitalMod runMod = Spellbook.GetSkillMod(RunSkillId);
+        System.Console.WriteLine(
+            System.FormattableString.Invariant(
+                $"[stat-chain] base run={_runSkillBase} jump={_jumpSkillBase} "
+                + $"runMod={runMod.Multiplier:F4}x+{runMod.Additive:F1} "
+                + $"-> eff run={run} jump={jump} "
+                + $"(activeEnchantments={System.Linq.Enumerable.Count(Spellbook.ActiveEnchantments)})"));
         MovementSkills.Update(run, jump);
     }