LANTERN P1: enemy-test gym tooling — on-demand spawn + GymTag clean-spawn

GymTag + GymEnemyRoster (+ GymRosterAuthoring) bake the gym singletons. New
DebugOp.SpawnEnemy (client SpawnEnemy wrapper + server receive case) spawns a
chosen enemy KIND (Drowner/Grindylow) from the baked roster near the sender —
replacing the wave-roster hack per the roadmap's Enemy-test GYM direction.
GoInGameServerSystem takes a GymTag branch: bypass the meta-catalog spawn guard
(a fresh gym has no CycleDirector) + seed a default Spark loadout on keys 1-4.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Assets/_Project/Scripts/Simulation/Debug/DebugCommandRequest.cs

@@ -68,5 +68,8 @@ namespace ProjectM.Simulation
         /// Strips the old class trait seeds, re-seeds the new ones, swaps the Fire ability, and heals a living
         /// player to the new class's max. Editor-only dev tool (class-switch); 0 / unknown -> Warrior.</summary>
         public const byte SetClass = 13;
+
+        /// <summary>GYM (editor): spawn <see cref="GymEnemyKind"/> ArgA near the sender, ArgB times (default 1). Reads the baked GymEnemyRoster.</summary>
+        public const byte SpawnEnemy = 14;
     }
 }

Assets/_Project/Scripts/Simulation/Debug/GymComponents.cs

@@ -0,0 +1,35 @@
+using Unity.Entities;
+
+namespace ProjectM.Simulation
+{
+    /// <summary>
+    /// Singleton tag baked into the Enemy-test GYM subscene (see the LANTERN roadmap A1 gym note). Marks the world
+    /// as the gym so <c>GoInGameServerSystem</c> takes the CLEAN gym spawn path — bypassing the base/meta/cycle
+    /// seeding (the gym has no CycleDirector, so the meta-catalog spawn guard must not block it) and seeding a
+    /// default Spark socket loadout instead. Purely a mode switch; the gym never runs the base siege/economy.
+    /// </summary>
+    public struct GymTag : IComponentData { }
+
+    /// <summary>
+    /// Baked gym enemy roster — one row per on-demand-spawnable enemy KIND (buffer index is arbitrary; match on
+    /// <see cref="Kind"/>). <c>DebugCommandReceiveSystem</c>'s SpawnEnemy op instantiates the row whose Kind ==
+    /// ArgA near the requesting player. Entity refs can't live in a blob, so this is a companion buffer on the
+    /// gym-roster entity (the <see cref="AbilityPrefabElement"/> idiom). Server-read only.
+    /// </summary>
+    [InternalBufferCapacity(4)]
+    public struct GymEnemyRoster : IBufferElementData
+    {
+        /// <summary>Stable enemy-kind key (0 = Drowner, 1 = Grindylow; extend as the roster grows).</summary>
+        public byte Kind;
+
+        /// <summary>The baked enemy ghost prefab entity to instantiate for this kind.</summary>
+        public Entity Prefab;
+    }
+
+    /// <summary>Stable kind ids for <see cref="GymEnemyRoster.Kind"/> / the SpawnEnemy op's ArgA.</summary>
+    public static class GymEnemyKind
+    {
+        public const byte Drowner = 0;
+        public const byte Grindylow = 1;
+    }
+}

Assets/_Project/Scripts/Simulation/Debug/GymComponents.cs.meta

@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: f39498494d08f66458393a87b395cd62