Sibling crate using egui/eframe. Click empty space to drop a node and
start a road from it; click a second node to close the road. Drag a
node to live-apply MoveNode (with snap-back on rejection). Side panel
exposes every SubdivisionParams knob, view toggles, and timing stats.
- Workspace Cargo.toml at repo root.
- RoadGraph::nodes() iterator added (needed to hit-test isolated
just-placed nodes that have no incident road yet).
- WASM target list is configured in Cargo.toml but native is the only
shipped frontend in this commit — WASM bundling lands next.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>