fix: support drag handles inside shadow DOM

[driskull]

Summary

• update drag handle validation to use the event composed path instead of point-based DOM lookup
• allow drag handle matching to work for handles rendered inside nested shadow roots
• update Playwright drag helpers so native and synthetic drag tests can target shadow-root elements
• add draghandle-shadow test coverage and a dedicated test page for the scenario

Why

Drag handles rendered inside shadow DOM were not recognized reliably because validation only queried light-DOM descendants from the draggable node. This change makes drag handle detection event-aware and shadow-DOM compatible.

Testing

• add native drag Playwright coverage for drag handles inside shadow DOM
• add synthetic drag Playwright coverage for drag handles inside shadow DOM
• verify dragging from the item body does not reorder
• verify dragging from the shadow-root handle reorders items as expected

#170

[vercel]

@driskull is attempting to deploy a commit to the Formkit Team on Vercel.

A member of the Team first needs to authorize it.