test: add unit tests for useHotkeys hook

[tdevelope]

Description

Adds unit tests for the useHotkeys custom hook, covering common and edge-case scenarios such as modifier keys, focus handling, and event cleanup.

• Fixes: Add test suites for Frontend files to bump overall coverage #352

Checklist

• Ran npx prettier --write . (for formatting)
• Ran gofmt -w . (for Go backend)
• Ran npm test (for JS/TS testing)
• Added unit tests, if applicable
• Verified all tests pass
• Updated documentation, if needed

Additional Notes

No production code was modified; this PR focuses solely on improving test coverage.

[github-actions]

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[its-me-abhishek]

LGTM! Thanks for the PR!