refactor: migrate onboarding/name page to Yamada UI

[mikais13]

Description

Replaced onboarding/name page components and styling with equivalents from Yamada UI.

Before:

After:

Fixes #116

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

• Manual testing (requires screenshots or videos)
• Integration tests written (requires checks to pass)

Checklist before requesting a review

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added thorough tests that prove my fix is effective and that my feature works
• I've requested a review from another user

[taroj1205]

LGTM Nice!