[WITHDRAWN] v1.3.1

Changes

• Fix false magnet detection on noisy signals (e.g. sensor startup spikes no longer mistaken for magnets)
• Add automatic dead zone detection — flat signal regions at start/end of recording are trimmed automatically
• Show "Trim" markers (blue) on chart when trimming is based on dead zones, distinct from "Magnes" markers (orange)
• Improve quality assessment messages to distinguish marker-based vs dead zone-based trimming
• Redesign UI to industrial style with clearer layout and section hierarchy