If damage is dealt to a unit by a spell before a showdown, does that damage persist into the showdown, and when does damage wear off?

Ruling: Damage dealt by spells before a showdown will persist into the showdown because spell damage is not combat damage. Units are healed after any combat and at the end of turn.

Nuances:

• Spell damage is distinct from combat damage
• Healing occurs after combat (which would include showdowns) and at end of turn