A drag started past a fixed 4 pixels from the press. In 1.12.1 the threshold is 0.01 layout units, where the screen diagonal is 1: `0x76b300` stores `0.01f × 0.01f` (`0x81c468`) as an f32, and `0x76b320` starts the drag when the squared distance from the press point is not below it, comparing at x87 double precision. The converters `0x425610`/`0x425710` scale the cursor into those units (`0x41ad80`).
The drag test now divides both points by the layout unit and compares the squared distance in f64 against the f32 threshold. At 1024×768 a drag needs 12.8 px, at 1920×1080 about 22 px; the UI scale does not change it.
Tests: just under and over 1% of the diagonal, 12 and 13 px at 1024×768, the exact f32 boundary, two screen sizes and three UI scales.
Fixes#157🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
