Find a live TrackerActionModel across all downs.
Find a live CombatDownModel by its downNumber.
Find a live TrackerEffectModel across all downs.
Find the index of the first non-empty down after index 0, or -1 if none. Used by advanceToNextResolution to determine step count.
StaticdefineStaticredistributeRedistribute all actions and effects in a plain-object downs array to their correct down slots by resolutionTime. Mutates the array in place. Called from _preUpdate before Foundry validation.
Plain-object downs array from toObject()
Classify which actions and effects are affected by advancing
stepsdowns. Returns live DataModel instances so callers can use .actor, .combatant, etc.