v0.5.0

Features

• Rollover highlight — the entity under the cursor is highlighted as the mouse moves over the drawing.
• Esc cancels an in-progress grip drag, restoring the entity to where it started; a normal release commits.
• PERF command toggles a frame-budget HUD showing the cost of the last wire re-tessellation.
• Open completion logs a parse / purge / caches / xref / total breakdown to the command line.

Performance

• Continuous interaction no longer re-tessellates the whole model: selecting, hovering, drawing-command previews and grip drags now refresh only what actually changed.
• Block-heavy edits: line-commit and grip start/end drop from ~400 ms to the ~30 ms baseline — a non-block edit no longer rebuilds every block definition (separate block_epoch).
• Panning reuses the cached tessellation and skips the wire-buffer GPU re-upload; only the camera matrix and scissors update.
• The wire pass is batched into per-run draw calls — a 2D model renders in a single draw instead of one per entity.
• Command-preview and grip-drag overlays draw from their own small GPU buffer, so the resident base wire buffer stays put during a drag.
• Faster file open — redundant entity walk dropped, the world-offset scan fused into the cache pass, corrupt-entity scan and block-definition build parallelized, and FxHash for the hot block / hatch / wire-cache maps.

Full Changelog: v0.4.9...v0.5.0