Plan2D.tsx

import { useEffect, useMemo, useRef, useState } from 'react';
import { useSceneStore } from '../scene/store';
import { polygonCentroid, wallLength, wallNormal, wallOpeningRects, wallUnit } from '../scene/geometry';
import {
  describeById,
  describeFixture,
  describeOpening,
  describeRoom,
  describeWall,
  SELECTED_COLOR,
  type Selected2D,
} from '../scene/describe';
import { Compass } from './Compass';
import { ZoomControls } from '../ui/ZoomControls';
import type { UnitSystem } from '../scene/units';
import type { Opening, Scene, Vec2, Wall } from '../scene/schema';

const PAD = 36; // inches of padding around scene bounds

function sceneBounds(scene: Scene): { minX: number; minY: number; maxX: number; maxY: number } {