fix: checkbox/radio/switch target size, check tag remove target #3363

Title: A11y: Checkbox/Switch/Radio label row and Tag remove target below WCAG 2.2 target size minimum (2.5.8)

Current behavior

• Checkbox label row: 109×21px (control itself 16×16px) – below the 24×24px minimum.
• Switch: 113×24px – right at the edge, no margin for measurement variance.
• Radio: likely the same pattern as Checkbox (needs confirming).
• Tag remove icon: not implemented as a real <button> – hit target unverified.

Expected behavior

WCAG 2.2 AA – 2.5.8 Target Size (Minimum) ⚠️ gap

→ To-do:

• Increase label row height/padding to 24px minimum for Checkbox, Switch, Radio
• Confirm Radio follows the same pattern as Checkbox
• Verify Tag's remove icon has a real interactive element (button) with a ≥24×24px hit target

Steps to reproduce

1. Open Storybook, inspect the label row of sd-checkbox / sd-switch / sd-radio in DevTools
2. Measure the clickable/tappable area (not just the visible control)
3. Compare against 24×24px CSS pixels

Storybook

• sd-checkbox: https://solid-design-system.fe.union-investment.de/docs/?path=/docs/components-checkbox--docs
• sd-switch: https://solid-design-system.fe.union-investment.de/docs/?path=/docs/components-switch--docs
• sd-radio: https://solid-design-system.fe.union-investment.de/docs/?path=/docs/components-radio--docs
• sd-tag: https://solid-design-system.fe.union-investment.de/docs/?path=/docs/components-tag--docs

Technical Information

DoR

• Item has business value
• Item has been estimated by the team
• Item is clear and well-defined
• Item dependencies have been identified