ApplyFieldConditionMutation
data class ApplyFieldConditionMutation(val conditionEffectId: String, val duration: Int? = null, val sourceId: String? = null) : BattleMutation
field condition 挂载变更。
设计意图：
承载
apply_condition target=field的正式结构化写回语义；让 Trick Room / Gravity / Magic Room / Wonder Room 这类场地公共规则不再挤进 side condition。