fix(editor): site-panel property-line coords + area/perimeter follow the unit toggle

The property-line vertex X/Z inputs and the Area/Perimeter readout were
hardcoded to meters. Convert them to feet / ft² when the viewer preference is
imperial, matching every other length input.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/editor/src/components/ui/sidebar/panels/site-panel/index.tsx

@@ -38,6 +38,11 @@ import {
 } from './../../../../../lib/level-duplication'
 import { getDefaultLevelName } from '@pascal-app/core'
 import { deleteLevelWithFallbackSelection } from './../../../../../lib/level-selection'
+import {
+  getLinearUnitLabel,
+  linearUnitToMeters,
+  metersToLinearUnit,
+} from './../../../../../lib/measurements'
 import { createLocalGuideImage } from './../../../../../lib/local-guide-image'
 import { cn } from './../../../../../lib/utils'
 import useEditor from './../../../../../store/use-editor'
@@ -93,6 +98,7 @@ const PropertyLineSection = memo(function PropertyLineSection() {
   const updateNode = useScene((state) => state.updateNode)
   const mode = useEditor((state) => state.mode)
   const setMode = useEditor((state) => state.setMode)
+  const viewerUnit = useViewer((state) => state.unit)
 
   if (!siteNode) return null
 
@@ -101,6 +107,14 @@ const PropertyLineSection = memo(function PropertyLineSection() {
   const perimeter = calculatePerimeter(points)
   const isEditing = mode === 'edit'
 
+  // Property-line coordinates and readouts follow the metric/imperial toggle.
+  const isImperial = viewerUnit === 'imperial'
+  const linearLabel = getLinearUnitLabel(viewerUnit)
+  const toDisplayLinear = (meters: number) => metersToLinearUnit(meters, viewerUnit)
+  const toStoredLinear = (display: number) => linearUnitToMeters(display, viewerUnit)
+  const displayArea = isImperial ? area * 10.763_910_417 : area
+  const displayPerimeter = toDisplayLinear(perimeter)
+
   const handleToggleEdit = () => {
     setMode(isEditing ? 'select' : 'edit')
   }
@@ -166,10 +180,16 @@ const PropertyLineSection = memo(function PropertyLineSection() {
       {/* Measurements */}
       <div className="relative flex gap-3 pr-3 pb-2 pl-10">
         <div className="text-muted-foreground text-xs">
-          Area: <span className="text-foreground">{area.toFixed(1)} m²</span>
+          Area:{' '}
+          <span className="text-foreground">
+            {displayArea.toFixed(1)} {isImperial ? 'ft²' : 'm²'}
+          </span>
         </div>
         <div className="text-muted-foreground text-xs">
-          Perimeter: <span className="text-foreground">{perimeter.toFixed(1)} m</span>
+          Perimeter:{' '}
+          <span className="text-foreground">
+            {displayPerimeter.toFixed(1)} {linearLabel}
+          </span>
         </div>
       </div>
 
@@ -184,21 +204,21 @@ const PropertyLineSection = memo(function PropertyLineSection() {
                 <input
                   className="w-16 rounded border border-border/50 bg-accent/50 px-1.5 py-0.5 text-foreground text-xs focus:border-primary focus:outline-none"
                   onChange={(e) =>
-                    handlePointChange(index, 0, Number.parseFloat(e.target.value) || 0)
+                    handlePointChange(index, 0, toStoredLinear(Number.parseFloat(e.target.value) || 0))
                   }
                   step={0.5}
                   type="number"
-                  value={point[0]}
+                  value={Number(toDisplayLinear(point[0]).toFixed(2))}
                 />
                 <label className="shrink-0 text-muted-foreground">Z</label>
                 <input
                   className="w-16 rounded border border-border/50 bg-accent/50 px-1.5 py-0.5 text-foreground text-xs focus:border-primary focus:outline-none"
                   onChange={(e) =>
-                    handlePointChange(index, 1, Number.parseFloat(e.target.value) || 0)
+                    handlePointChange(index, 1, toStoredLinear(Number.parseFloat(e.target.value) || 0))
                   }
                   step={0.5}
                   type="number"
-                  value={point[1]}
+                  value={Number(toDisplayLinear(point[1]).toFixed(2))}
                 />
                 <button
                   className={cn(