Phase 1 B3: enemies die with a corpse window instead of popping out of existence

Server: HealthApplyDamageSystem marks EnemyTag Dying{UntilTick} (TickUtil.
NonZero, ~54 ticks) on the lethal 0-crossing instead of instant destroy,
zeroes every live cue (replicated AttackWindup, LungeState + IsLunging bit,
KnockbackState), destroys on expiry; plain-world tests keep instant destroy
(no NetworkTime) so the suite's assertions stay meaningful.

Every consumer now ignores corpses (all confirmed entity-count/unfiltered by
the design review): EnemyAISystem all 4 passes, BossAISystem brain + summon
cap, RoomEnemyDirector room-clear + MaxAlive fit, WaveSystem cap + cleared,
CyclePhaseSystem breach wipe + DefendCleared, ThreatDirector timeout cull,
TurretFire targeting, CoreDamage drain, ProjectileDamage snapshot (corpses
are not shields), AbilityFire auto-aim candidates, debug cull + telemetry.
Wipe passes skip Dying to avoid cross-ECB double-destroys.

Client: EnemyAnimationDriveSystem finally drives the controller's IsDead
param (Health.Current<=0 is the replicated death read; corpse locomotion
zeroed); CombatFeedbackSystem moves the kill CRUNCH to the 0-crossing (the
prune-edge timing would land it ~1 s late) - the prune keeps a small
dissolve puff for corpses and the legacy full read for alive-vanish culls.

456/456 EditMode.

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

Assets/_Project/Scripts/Simulation/Tuning.cs

@@ -95,6 +95,10 @@ namespace ProjectM.Simulation
         /// polish; an idle player died in ~2 s of landing). Subsequent slots keep the normal drip cadence.</summary>
         public const uint RoomEntryGraceTicks = 100;
 
+        /// <summary>Phase 1 (B3) corpse window (~0.9 s @60): a dead enemy lingers as a non-acting, non-counting,
+        /// non-targetable corpse so the client death animation has time to read before the despawn burst.</summary>
+        public const uint EnemyDeathWindowTicks = 54;
+
         // ---- Expedition BOSS (a scaled Charger given a real kit by BossAISystem; server-only feel consts) ----
 
         /// <summary>Radial SLAM AoE radius (world units): a player inside this ring at wind-up elapse eats the hit