Release v0.3.1: per-side edge collapse buttons Place collapse buttons on the side where edges actually exit (top/right/ bottom/left) instead of a single button fixed on the right. Each button independently collapses/expands only the edges on its side, with badge counts reflecting the per-side subtree. Buttons offset further outward to avoid overlapping anchor points. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>