feat(mobile): implement useAvoidKeyboard function

[zztnrudzz13]

Overview

Summary

This PR introduces the useAvoidKeyboard hook, which helps fixed-bottom elements (such as FixedBottomCTA) smoothly avoid the on-screen keyboard.

Features

• style: Ready-to-use CSS style object containing transform and transition properties
• keyboardHeight: Current keyboard height in pixels
• isKeyboardVisible: Boolean indicating whether the keyboard is currently visible

Checklist

• Did you write the test code?
• Have you run yarn run fix to format and lint the code and docs?
• Have you run yarn run test:coverage to make sure there is no uncovered line?
• Did you write the JSDoc?

[zztnrudzz13]

this PR is stacked, so please review only this commit!

[kimyouknow]

LGTM!