fix: RangeCalendar range selection in shadow DOM

[AKnassa]

Closes #10330

When a RangeCalendar (including the calendar inside DateRangePicker) is rendered inside a shadow root with enableShadowDOM(), clicking a single date immediately committed a range where start === end, so a multi-day range could never be selected by clicking.

The window-level pointerup listener in useRangeCalendar read the raw e.target. For events coming from inside a shadow root the browser retargets that to the shadow host, so the calendar always believed the pointer was released outside of it and committed the in-progress selection on every click. The listener now resolves the real target with the existing shadow-safe getEventTarget() helper, as suggested by @snowystinger in the issue.

✅ Pull Request Checklist:

• Included link to corresponding React Spectrum GitHub Issue.
• Added/updated unit tests and storybook for this change (for new code or code which already has tests).
• Filled out test instructions.
• Updated documentation (if it already exists for this component).
• Looked at the Accessibility Practices for this feature - Aria Practices

📝 Test Instructions:

1. yarn jest packages/react-aria-components/test/RangeCalendar.test.tsx — the new shadow DOM describe contains a click-selection test that fails without the fix (onChange fires with start === end on the first click) and passes with it, plus a test guarding that releasing a drag outside the calendar still commits the selection.
2. Manual: call enableShadowDOM() from @react-stately/flags, render a RangeCalendar inside an open shadow root, and click two dates — the range commits only on the second click, matching light DOM behavior.

🧢 Your Project:

No response