feat(gas): GameMode aponta pra BPs (Pawn/PlayerState) + cleanup ZeusCharacter

ZeusGameMode.cpp:
- DefaultPawnClass: usa FClassFinder pra /Game/ZMMO/Core/Player/BP_ZeusPlayerCharacter
  (fallback AZeusCharacter). Sem isso, engine instancia C++ direto e perde
  toda customizacao BP (EnhancedInputAction events, AnimBP wire, componentes
  BP-added).
- PlayerStateClass: usa FClassFinder pra /Game/ZMMO/Core/Player/BP_PlayerState
  (fallback AZeusPlayerState). Mesmo motivo -- BP filho tem componentes (ex:
  UZeusGASComponent via ComponentClasses no DefaultGame.ini) e overrides do
  designer que classes C++ puras nao tem.
- TODO: renomear BP_PlayerState -> BP_ZeusPlayerState (alinhar com convencao
  BP_ZeusPlayerCharacter); path do FClassFinder ja preparado pra renomear.

ZeusCharacter.cpp/h cleanup:
- Removida gambiarra anterior (PossessedBy + OnRep_PlayerState overrides +
  RefreshGASAvatar com FTimerHandle retry). Substituida pelo pattern
  event-driven em UZeusGASComponent::HandlePawnSet (commit server anterior).
- Includes desnecessarios (AbilitySystemComponent.h + ZeusAbilitySystemComponent.h)
  removidos.

ZMMO.uproject:
- GameplayAbilities adicionado em Plugins (UE 5.7 exige que modulo do jogo
  declare explicitamente plugins que ele consome -- antes vinha transitivamente
  do plugin ZeusGAS, gerava warning de build).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

ZMMO.uproject

@@ -76,6 +76,10 @@
 		{
 			"Name": "CommonUI",
 			"Enabled": true
+		},
+		{
+			"Name": "GameplayAbilities",
+			"Enabled": true
 		}
 	],
 	"AdditionalPluginDirectories": [