feat(button): migrate kol-button to Skeleton Blueprint architecture

[Copilot]

Migrates kol-button from the legacy dual-component pattern (shadow wrapper + internal WC) to the layered Skeleton Blueprint architecture, unifying it into a single shadow component with clean separation of concerns.

New files

src/internal/props/ — 13 new prop definitions

Each prop encapsulates normalization and validation via createPropDefinition:
access-key, alternative-button-link-role, aria-controls, aria-description, aria-expanded, aria-selected, button-type, button-variant, custom-class, disabled, inline, short-key, tab-index

src/internal/functional-components/button/

• api.tsx — buttonPropsConfig (PropsConfigShape) + ButtonApi derived via ApiFromConfig; declares Callbacks, Methods, and Refs (including tooltipFloating for type-safe tooltip ref wiring)
• controller.ts — ButtonController extends BaseController<ButtonApi>; receives StateAccess<ButtonApi>; delegates tooltip lifecycle to an internal TooltipController; exposes setTooltipFloatingRef to avoid unsafe prop hacks
• component.tsx — stateless ButtonFC; extends FunctionalComponentProps<ButtonApi> with a local tooltipId?: string intersection to replace the previous Record<string, unknown> cast

Modified files

• src/components/button/component.tsx — replaces both old files; extends BaseWebComponent<ButtonApi>; full prop triangle for all 18 props; form integration via AssociatedInputController
• src/components/button/snapshot.spec.tsx — co-located (moved from test/); expanded from 8 to 19 test cases covering _accessKey, _shortKey, _inline, _hideLabel, _icons, _customClass/custom variant, and all _type values

Deleted files

• src/components/button/shadow.tsx — legacy wrapper component; superseded by the unified shadow WC
• src/components/button/test/ — replaced by co-located tests

Architecture at a glance

KolButton (WebComponent)
  └── ButtonController (BaseController)          ← validates/normalizes props, manages tooltip
        └── ButtonFC (stateless renderer)        ← pure JSX, BEM classes, no side-effects

[github-actions]

Netlify Draft Deployment
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[github-actions]

🚀 MCP preview deployed to Vercel: https://kolibri-it4h5sbvk-public-ui-kolibri-mcp.vercel.app