New nodes were placed at (0,0) or close to it, causing them to spawn
behind the toolbar/palette chrome and require manual panning to find.
Add GRID_ORIGIN_X/Y = 100 offset so the first node lands in clear canvas
space, and update the position assertion in the unit test accordingly.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>