feat(react-headless-components-preview): add color picker controls

[dmytrokirpa]

Motivation

Add an unstyled color picker family to @fluentui/react-headless-components-preview. The controls reuse the state and interaction behavior extracted in #36517 while leaving layout and visual treatment to consumers.

Changes

• add headless ColorPicker, ColorArea, ColorSlider, and AlphaSlider components
• compose the controls from @fluentui/react-color-picker base hooks and the shared color picker context
• expose state through DOM data attributes such as data-channel, data-orientation, and data-transparency for consumer styling
• support both coordinated use inside ColorPicker and standalone controlled or uncontrolled controls
• export the component family through the single color-picker package entry point and update the API report
• add conformance and behavior tests for the new component family
• add Storybook examples demonstrating composed and standalone usage
• include the controls in the bundle-size fixture
• add the package dependency, lockfile update, and minor changefile for @fluentui/react-headless-components-preview

Review guidance

This PR should be reviewed relative to feat/color-picker-headless-base, not master. The component layer intentionally adds no Griffel styles; the stories provide example consumer styling only. The most relevant areas are the base-hook composition, the shared package entry point, native range-input semantics, and context coordination.

Validation

• yarn nx run-many -t lint test -p react-headless-components-preview --nxBail
• 70 test suites passed

PR stack

1. feat(react-color-picker): expose headless base APIs #36517: expose reusable color picker base APIs
2. This PR: add the headless color picker controls

Depends on #36517 and should be merged after it.

[github-actions]

Pull request demo site: URL