feat(mana): PlayerManager 换杖置蓝池 + 每帧回蓝

scripts/domain/player_manager.gd

@@ -28,6 +28,7 @@ func _ready() -> void:
 	EventBus.subscribe(EventID.ENEMY_KILLED, _on_enemy_killed)
 
 func _physics_process(delta: float) -> void:
+	PlayerStats.regen_mana(delta)
 	_handle_movement(delta)
 	_handle_charge_state(delta)
 	_handle_auto_cast(delta)
@@ -85,6 +86,10 @@ func equip_wand(core: CoreDefinition, compiled: CompiledDeck) -> void:
 	_equipped_compiled = compiled
 	_cast_interval     = core.cast_interval if core else 0.5
 	_cast_timer        = 0.0
+	if core:
+		PlayerStats.set_mana_pool(core.base_mana_max, core.base_mana_regen)
+	else:
+		PlayerStats.set_mana_pool(100.0, 5.0)
 
 func get_position() -> Vector2:
 	return _position