Boss becomes a real fight + readable-but-fair enemy threat

BossState (server-only) + BossAISystem: sole mover, seek -> telegraphed
radial slam (AttackWindup) -> phase-2 speed + swarmer summon. Excluded from
the EnemyAISystem Charger pass; knockback-immune at all 3 stamp sites;
arena-anchored spawn; scaled Health/HitRadius/AttackRange. Grunt windup now
commits in its last ~30% (whiffs out-of-range); Charger stagger roots; grunt
speed 4.2->5.2; swarmer telegraph synced. SweptMove + zone-enemy spawn-stamp
extracted to shared helpers. Zero new [GhostField].

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

Assets/_Project/Scripts/Simulation/Player/MeleeComboSystem.cs

@@ -49,6 +49,8 @@ namespace ProjectM.Simulation
     public partial struct MeleeComboSystem : ISystem
     {
         ComponentLookup<KnockbackState> m_KnockbackLookup;
+        ComponentLookup<BossState> m_BossLookup; // A4: the boss is knockback-immune (no melee stunlock out of its slams)
+
         ComponentLookup<RegionTag> m_RegionLookup;
         BufferLookup<InventorySlot> m_InvLookup;
         BufferLookup<StatModifier> m_StatModLookup;
@@ -57,6 +59,8 @@ namespace ProjectM.Simulation
         public void OnCreate(ref SystemState state)
         {
             m_KnockbackLookup = state.GetComponentLookup<KnockbackState>(isReadOnly: false);
+            m_BossLookup = state.GetComponentLookup<BossState>(isReadOnly: true);
+
             m_RegionLookup = state.GetComponentLookup<RegionTag>(isReadOnly: true);
             m_InvLookup = state.GetBufferLookup<InventorySlot>(isReadOnly: false);
             m_StatModLookup = state.GetBufferLookup<StatModifier>(isReadOnly: true);
@@ -224,6 +228,8 @@ namespace ProjectM.Simulation
 
 
                 m_KnockbackLookup.Update(ref state);
+                m_BossLookup.Update(ref state);
+
                 var ecb = new EntityCommandBuffer(Allocator.Temp);
                 for (int s = 0; s < cleaves.Length; s++)
                 {
@@ -239,7 +245,7 @@ namespace ProjectM.Simulation
                             SourceNetworkId = c.OwnerId,
                             SourceTick = c.Stamp,
                         });
-                        if (c.KnockSpeed > 0f && m_KnockbackLookup.HasComponent(target))
+                        if (c.KnockSpeed > 0f && m_KnockbackLookup.HasComponent(target) && !m_BossLookup.HasComponent(target))
                         {
                             float3 d3 = enemyPositions[i] - c.From;
                             float2 kdir = new float2(d3.x, d3.z);