feat(editor): preset-system polish — paint panel, slim action bar, icon rail (#354)

* feat(editor): preset-system polish — paint panel, slim action bar, icon rail

- Export `MaterialPaintPanel` so embedders host the paint material picker in
  their own panel (community docks it in the Build sidebar) instead of the
  bottom action bar.
- ActionMenu: drop the build / material-paint / furnish modes and the
  structure-tools palette row + paint tray (the host's Build sidebar owns
  building now). Reduce `structure-tools` to the shared `tools` lookup still
  used by cursor/floorplan indicators; remove the orphaned `useContextualTools`.
- MaterialPicker: swatches wrap into a fluid `auto-fill` grid that fills width.
- IconRail (tab-bar): bigger icons, grayscale-when-idle, Radix tooltip, w-14
  rail; sync `RAIL_WIDTH` to 56.
- Inspector footer: hand the host `footer` to kind-owned custom panels via
  `InspectorFooterContext` so the save button renders without per-kind wiring.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* chore: biome format pass

Whole-repo formatter normalization (line wrap/unwrap only, no logic changes)
surfaced by the format-on-edit hook against prior drift. Kept separate from the
feature commit so the preset-system diff stays reviewable.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

packages/viewer/src/components/renderers/parametric-node-renderer.tsx

@@ -62,10 +62,7 @@ export const ParametricNodeRenderer = ({ node }: { node: AnyNode }) => {
   // of snapping only on commit. Per-node subscription so unrelated
   // override writes don't re-render the whole tree.
   const liveOverride = useLiveNodeOverrides((s) => s.overrides.get(node.id))
-  const overrideRotation = liveOverride?.rotation as
-    | [number, number, number]
-    | number
-    | undefined
+  const overrideRotation = liveOverride?.rotation as [number, number, number] | number | undefined
   const overridePosition = liveOverride?.position as [number, number, number] | undefined
 
   useRegistry(node.id, node.type, ref)