Question
Do I have to report a repair done by a neighbour?
Whether a repair done by a neighbour has to be reported depends on what changed. Damage, a theft, and anything that changes what is in the home or what the building is, all get reported. Nothing else does.
Work done as a favour still leaves a record, as long as somebody writes down what was done, when, and with which materials.
A repair that was paid for has an invoice. A repair that was not has a date and two people who remember it, and a note written the same week keeps that.