Polish three-floor-townhouse example: single-floor plan with color controls

[aka-blackboots]

Summary

• Rewrites examples/src/three-floor-townhouse.html as one detailed 18 × 14 m single-floor home (foyer, living, dining, garage, kitchen, mudroom, master suite + ensuite + walk-in, two more bedrooms, shared bath, laundry) — better suited to showcasing OpenPlans as a floorplan tool than the cramped multi-floor original.
• Adds a true profile / model toggle: profileView / modelView flags flip on every wall + door + window, alongside CameraMode, scene background, body class, and slab visibility — so the two modes look genuinely distinct, not just differently projected.
• Adds drafting overlays in plan mode: room labels projected from world space each frame, a live scale bar computed from the camera projection, and a north arrow.
• Adds a color controls panel: 6 native <input type="color"> pickers (Ext Wall, Int Wall, Door Panel, Door Frame, Glass, Win Frame) plus 4 preset palettes (Warm Paper, Blueprint, Mono, Dusk). Door / window pickers update live on input; wall pickers commit on change and trigger wall.setOPGeometry() to rebuild — works around the empty SingleWall.setOPMaterial stub without touching the library.
• Wall fills are realistic light tones in every preset; the dark drafted look in plan mode comes from wall.outline strokes rather than dark fills.

Notes for reviewers

• Only examples/src/three-floor-townhouse.html is changed.
• The SingleWall.setOPMaterial stub is a known library limitation — turning it into a real implementation would let wall pickers update live like doors / windows do. Out of scope here.
• The pre-existing local edit to src/packages/openplans-three/src/three.ts (logarithmicDepthBuffer: true → false) was present before this branch and is not included.

Test plan

• npm run dev, open /three-floor-townhouse.html.
• Plan view: walls render with light fills + dark outlines; room labels track pan / zoom; scale bar updates and snaps to nice values; north arrow visible.
• Model view: 3D walls with cut openings, doors and windows visible, slab below.
• Toggle plan ↔ model several times — no leaked overlays, no console errors, reset-view re-fits correctly.
• Drag door panel / glass pickers → live update across the scene.
• Drag exterior wall picker → no change while dragging; release → walls rebuild with new color and openings stay cut.
• Cycle through all four presets → all six pickers + scene update together.

🤖 Generated with Claude Code