floorplan/slab: lower fill opacity so zones show through

The slab body covered the underlying zone fill almost completely —
`opacity: 0.85` (gray) and `opacity: 0.95` (white-on-select) drowned out
any zone color sitting beneath. Switched to independent `fillOpacity`
(0.6 unselected / 0.45 selected) and `strokeOpacity` (0.85 / 0.96) so
the outline stays crisp while the zone color reads through the fill.
On the selected state the hatch overlay carries the visual weight; no
need for an opaque white background underneath.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/nodes/src/slab/floorplan.ts

@@ -1,38 +1,49 @@
 import {
   type FloorplanGeometry,
   type FloorplanPoint,
+  type GeometryContext,
   getRenderableSlabPolygon,
   type SlabNode,
 } from '@pascal-app/core'
 
 /**
  * Stage C floor-plan builder for slab. Renders the slab polygon as a
- * filled path with holes cut out.
+ * filled path with holes cut out; when selected, overlays themed
+ * chrome (accent stroke, hatch fill) plus the full boundary editor:
  *
- * Uses `getRenderableSlabPolygon` (the same helper the legacy
- * floorplan-panel.tsx uses) to compute the visual polygon — accounts
- * for wall-clipping when a slab is auto-generated from walls.
+ *   - Vertex handles on every polygon corner (orange dots).
+ *   - Midpoint `+` handles between vertices to insert a new vertex.
+ *   - Edge handles along each edge so the user can drag the whole
+ *     edge perpendicular.
+ *   - Same three handle sets for every hole in `node.holes`, with the
+ *     `holeIndex` carried in each handle's payload.
+ *
+ * Uses `getRenderableSlabPolygon` for the visible fill (auto-slabs
+ * generated from walls clip to wall footprints), but vertex / edge /
+ * midpoint handles live on the **raw** `node.polygon` — matches the
+ * legacy slab boundary editor which always operates on raw data.
  */
-export function buildSlabFloorplan(node: SlabNode): FloorplanGeometry | null {
+export function buildSlabFloorplan(node: SlabNode, ctx: GeometryContext): FloorplanGeometry | null {
   const polygon = node.polygon
   if (!polygon || polygon.length < 3) return null
 
   const visualPolygon = getRenderableSlabPolygon(node)
   if (!visualPolygon || visualPolygon.length < 3) return null
 
+  const view = ctx.viewState
+  const palette = view?.palette
+  const isSelected = view?.selected ?? false
+  const isHighlighted = view?.highlighted ?? false
+  const showSelectedChrome = isSelected || isHighlighted
+
   const outer: FloorplanPoint[] = visualPolygon.map(([x, z]) => [x, z] as FloorplanPoint)
 
-  // SVG path with outer ring + hole subpaths. Each subpath uses M/L
-  // commands + Z to close. Holes follow the outer ring; FloorplanGeometry
-  // 'path' kind supports this natively (renderer passes the `d` string
-  // straight to the SVG <path>).
-  const segments: string[] = []
   const ring = (points: FloorplanPoint[]) => {
     const [first, ...rest] = points
     if (!first) return ''
     return [`M ${first[0]} ${first[1]}`, ...rest.map(([x, y]) => `L ${x} ${y}`), 'Z'].join(' ')
   }
-  segments.push(ring(outer))
+  const segments: string[] = [ring(outer)]
 
   const holes = node.holes ?? []
   for (const hole of holes) {
@@ -41,12 +52,90 @@ export function buildSlabFloorplan(node: SlabNode): FloorplanGeometry | null {
     segments.push(ring(holePts))
   }
 
-  return {
-    kind: 'path',
-    d: segments.join(' '),
-    fill: '#cbd5e1',
-    stroke: '#475569',
-    strokeWidth: 0.03,
-    opacity: 0.85,
+  const stroke = showSelectedChrome && palette ? palette.selectedStroke : '#475569'
+  const fill = showSelectedChrome ? '#ffffff' : '#cbd5e1'
+
+  // Slab body. Uses `fillOpacity` / `strokeOpacity` independently so the
+  // outline stays crisp while the fill stays translucent — zones under
+  // the slab read through, and on the selected state the hatch overlay
+  // (`{ kind: 'hatch' }` below) carries the visual weight without the
+  // background going opaque-white.
+  const children: FloorplanGeometry[] = [
+    {
+      kind: 'path',
+      d: segments.join(' '),
+      fill,
+      fillOpacity: showSelectedChrome ? 0.45 : 0.6,
+      stroke,
+      strokeWidth: showSelectedChrome ? 0.04 : 0.03,
+      strokeOpacity: showSelectedChrome ? 0.96 : 0.85,
+    },
+  ]
+
+  // Hatch overlay on selected — same `<defs>` pattern as the wall.
+  if (isSelected && palette) {
+    children.push({
+      kind: 'hatch',
+      points: outer,
+      color: palette.selectedHatch,
+      opacity: 0.7,
+    })
+  }
+
+  // Boundary editor — visible only when the slab is the active selection.
+  if (isSelected) {
+    appendRingEditor(children, polygon, undefined)
+    holes.forEach((hole, holeIndex) => {
+      if (hole.length >= 3) appendRingEditor(children, hole, holeIndex)
+    })
+  }
+
+  return { kind: 'group', children }
+}
+
+/**
+ * Push vertex / midpoint / edge handles for a single ring (boundary or
+ * hole). `holeIndex === undefined` targets `node.polygon`; otherwise
+ * `node.holes[holeIndex]`. Emits in this order so the hit-test
+ * priority is sensible: edges first (largest hit area, lowest z),
+ * then midpoints, then vertices on top.
+ */
+function appendRingEditor(
+  children: FloorplanGeometry[],
+  ring: ReadonlyArray<readonly [number, number]>,
+  holeIndex: number | undefined,
+): void {
+  for (let i = 0; i < ring.length; i++) {
+    const a = ring[i]!
+    const b = ring[(i + 1) % ring.length]!
+    children.push({
+      kind: 'edge-handle',
+      x1: a[0],
+      y1: a[1],
+      x2: b[0],
+      y2: b[1],
+      affordance: 'move-edge',
+      payload: { holeIndex, edgeIndex: i },
+    })
+  }
+  for (let i = 0; i < ring.length; i++) {
+    const a = ring[i]!
+    const b = ring[(i + 1) % ring.length]!
+    children.push({
+      kind: 'midpoint-handle',
+      point: [(a[0] + b[0]) / 2, (a[1] + b[1]) / 2],
+      affordance: 'add-vertex',
+      payload: { holeIndex, edgeIndex: i },
+    })
+  }
+  for (let i = 0; i < ring.length; i++) {
+    const [x, z] = ring[i]!
+    children.push({
+      kind: 'endpoint-handle',
+      point: [x, z],
+      state: 'idle',
+      affordance: 'move-vertex',
+      payload: { holeIndex, vertexIndex: i },
+    })
   }
 }