Migrate TimeRangePicker (dial) to Floating UI

[qroll]

Component
TimeRangePicker dial variant

Describe the feature request
Part of #443 for improved dropdown display and positioning

• Migrate TimeRangePicker (dial variant) to use the shared FloatingUI dropdown utility
• Expose the alignment, dropdownZIndex, and dropdownRootNode props and document them in Storybook
• Create unit tests to assert the selection and blur/focus behaviour

Acceptance criteria

• Component follows the DS styling in Figma
• Dropdown auto-positions when the user scrolls on the page
• Unit tests should pass

References
TimeRangePicker Figma