Add keyboard shortcut hint on ClaimFlow (v7)

[greatest0fallt1me]

Description

This is a UI/UX issue for the GrantFox campaign. This is a UI/UX issue for the GrantFox FWC26 campaign (Stellar Wave). Show keyboard shortcut hint on ClaimFlow.

Requirements and Context

• Implement per the description
• Add focused tests
• Document any API/visible changes
• Adhere to repo's lint and code style
• Must be secure, tested, and documented
• Should be efficient and easy to review

Suggested Execution

1. Fork the repo and create a branch

   git checkout -b task/claimflow-kbd-v7

2. Implement changes
   • src/pages/ClaimFlow.tsx
   • src/components/KbdHint.tsx
3. Test and commit
   • Run the repo's standard test suite and lint
   • Cover edge cases; include output in the PR

Example commit message

feat: ClaimFlow kbd hints

Acceptance Criteria

• Implementation matches the description
• Tests added and passing
• Code review approved
• Docs updated

Guidelines

• Responsive across all breakpoints
• WCAG 2.1 AA accessibility
• Design-token + dark-mode consistency
• Clear documentation and inline comments
• Timeframe: 96 hours