Fix "Expand map" tooltip overlapping message composer

[Tamajit-005]

Fixes #21619

Summary

The "Expand map" tooltip on location messages was rendered through a FloatingPortal, allowing it to overlap UI elements outside the visible message panel, including the message composer while scrolling.

The existing compound-web <Tooltip> component does not expose the Floating UI middleware required to implement boundary-aware positioning and visibility behavior.

This change replaces the tooltip with a custom BoundaryAwareTooltip built on @floating-ui/react that:

• Flips above the map when there is insufficient space below it
• Hides when it escapes the visible message panel boundary

Before

The tooltip remains visible and can overlap the message composer when the timeline is scrolled.

After

The tooltip flips above the map when space below becomes constrained and becomes hidden when it escapes the visible message panel boundary.

Demonstration

Screencast.from.2026-05-30.18-15-20.mp4

A short screen recording is attached to demonstrate the scrolling behavior, tooltip flipping, and boundary-aware hiding. The issue and fix are easier to observe in motion than through static screenshots.

Testing

1. Open a room containing a location message
2. Hover over the map and verify the "Expand map" tooltip appears
3. Scroll down so the map approaches the message composer
4. Verify the tooltip flips above the map instead of overlapping the composer
5. Continue scrolling until the tooltip would escape the visible message panel boundary
6. Verify the tooltip becomes hidden
7. Run:

cd apps/web
pnpm exec jest --no-coverage test/unit-tests/components/views/messages/MLocationBody-test.tsx

Expected result:

• 6 tests pass
• 4 snapshots pass

Notes

• Adds @floating-ui/react as a direct dependency (previously only available transitively through @vector-im/compound-web)
• Includes a separate commit adding matrix-js-sdk to Jest's transformIgnorePatterns
• The Jest change addresses a pre-existing test infrastructure issue encountered while running the location message test suite and is intentionally isolated from the feature change for easier review

Checklist

• I have read through review guidelines and CONTRIBUTING.md.
• Tests written for new code (and old code if feasible).
• New or updated public/exported symbols have accurate TSDoc documentation.
• Linter and other CI checks pass.
• I have licensed the changes to Element by completing the Contributor License Agreement (CLA)

[Tamajit-005]

The CI Preview Changelog check is failing because this PR needs a T-Defect label. Could a maintainer add it?