parametrics: add display: 'segmented' enum hint + drop fence color

User pointed out two regressions in the auto-derived fence inspector:

- A `color` field rendered for fence — but the legacy `FencePanel`
  hid it (fence's color is a leftover schema field that isn't part of
  the inspector UX). Dropped from `fenceParametrics`.

- Style + base-style enums rendered as a dropdown, but the legacy
  used the inline segmented switcher (Slat/Rail/Privacy +
  Grounded/Floating). Added a `display?: 'select' | 'segmented'` hint
  to the enum field kind. ParametricInspector renders SegmentedControl
  when set; defaults to dropdown otherwise.

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

packages/nodes/src/fence/parametrics.ts

@@ -32,10 +32,19 @@ export const fenceParametrics: ParametricDescriptor<FenceNode> = {
     {
       label: 'Style',
       fields: [
-        { key: 'style', kind: 'enum', options: ['slat', 'rail', 'privacy'] },
-        { key: 'baseStyle', kind: 'enum', options: ['floating', 'grounded'] },
+        {
+          key: 'style',
+          kind: 'enum',
+          options: ['slat', 'rail', 'privacy'],
+          display: 'segmented',
+        },
+        {
+          key: 'baseStyle',
+          kind: 'enum',
+          options: ['grounded', 'floating'],
+          display: 'segmented',
+        },
         { key: 'showInfill', kind: 'boolean' },
-        { key: 'color', kind: 'color' },
       ],
     },
   ],