🎨 Palette: Improve MatchPreviewModal Accessibility & Keyboard Navigation

[jspann21]

💡 What: Improved the accessibility of the MatchPreviewModal.

1. Added a global keydown event listener for the Escape key that closes the modal.
2. Added role="dialog" and aria-modal="true" to the modal's container element.
3. Added a native HTML title attribute to the candidate titles in the selection list.

🎯 Why:
Custom modal components (built with divs rather than native <dialog> elements) lack native keyboard and screen-reader behaviors.

• Without an Escape key listener, keyboard users are forced to tab to the "Cancel" button.
• Without ARIA attributes, screen reader users may not realize their focus is trapped within a modal context.
• The titles in the match list use CSS truncation (truncate), meaning long titles were permanently cut off. Adding the title attribute enables a native OS tooltip so users can read the full text before confirming a match.

📸 Before/After:
(Visual changes are minimal, primarily consisting of the native OS tooltip appearing when hovering over truncated titles in the list)

♿ Accessibility:

• Ensures screen readers announce the component as an active dialog (role="dialog", aria-modal="true").
• Enables standard keyboard-dismissal patterns (Escape to close).
• Makes truncated text readable via standard tooltip mechanisms.

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PR created automatically by Jules for task 11510507886073752544 started by @jspann21

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