feat(builder): text+button package -- typography depth, button target/hover, box-model+anim/vis rollout

- TextStylePanel (Heading/TextBlock): line-height/letter-spacing presets,
  text-transform (none/uppercase/lowercase/capitalize), italic + underline
  toggles (fontStyle/textDecoration), and a custom NumericUnitInput
  font-size alongside the existing preset row. All write to component
  `style`; no toHtml changes needed (style already flows through
  cssPropsToString for both components).
- ButtonStylePanel/ButtonLink: "Open in new tab" checkbox writes the
  existing `target` prop ('_self'/'_blank' -- toHtml already emitted
  rel="noopener noreferrer" for _blank). New Hover State section
  (hoverBg/hoverColor via ColorPickerField) renders a scoped
  `<style>.btn_<hash>:hover{...}</style>` block before the `<a>` in
  toHtml, scoped per-node via scopeId (same pattern as Navbar/Menu) so
  two buttons on one page don't collide; both values sanitized through
  cssValue against <style>-element breakout. Editor canvas gets a live
  hover preview via onMouseEnter/onMouseLeave local state (mirrors Menu's
  approach), since there's no way to preview a CSS :hover rule directly
  on an inline-styled React element.
- Heading/TextBlock/ButtonLink: added margin(per-side)/padding(per-side,
  Text only)/border/box-shadow/opacity style defaults + AnimationControl/
  VisibilityControl-backed animation/animationDelay/hideOnDesktop/
  hideOnTablet/hideOnMobile props, each panel gaining collapsible
  Spacing / Border & Effects / Animation & Visibility sections. Button
  keeps its existing padding-shorthand preset row rather than adding a
  redundant per-side padding control; only margin got the new
  per-side SpacingControl.
- Tests: extended all three *.toHtml.test.ts files -- typography style
  emission (line-height/letter-spacing/text-transform/font-style/
  text-decoration/custom font-size), button target+rel, scoped hover
  style emission + two adversarial style-breakout cases (</style><script>
  and rule-injection via `;}selector{`), and craft.props assertions for
  every new prop on all three components. 674 tests green, tsc + vite
  build clean.

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

craft/src/components/basic/Heading.tsx

@@ -100,7 +100,22 @@ Heading.craft = {
       fontFamily: 'Inter, sans-serif',
       color: '#1f2937',
       marginBottom: '16px',
+      lineHeight: '',
+      letterSpacing: '',
+      textTransform: '' as CSSProperties['textTransform'],
+      fontStyle: '' as CSSProperties['fontStyle'],
+      textDecoration: '',
+      marginTop: '', marginRight: '', marginLeft: '',
+      paddingTop: '', paddingRight: '', paddingBottom: '', paddingLeft: '',
+      border: 'none',
+      boxShadow: 'none',
+      opacity: '1',
     },
+    animation: '',
+    animationDelay: '0',
+    hideOnDesktop: false,
+    hideOnTablet: false,
+    hideOnMobile: false,
   },
   rules: {
     canDrag: () => true,