What We Know
The current community-tested answer is tied to the second-floor repair and enchanting machine. Reported use costs 100 gold, restores an eligible item to full durability, and adds an enhancement.
Steps or Conditions
First unlock access to the second floor. Bring a valid damaged item and enough gold to the repair and enchanting machine. The page intentionally says eligible item because current evidence does not support a complete compatibility list.
What Does Not Work
Healing Glue is not a general weapon repair method. Do not assume every item can use the machine or that an NPC line about another repair option means that option is already available.
Evidence and Limits
This is CAVEAT content because the machine behavior and price are community-confirmed and can change with the launch build. Verify the condition and cost again after a repair-system update.