feat: add shortcut to replay onboarding tour

[Jeevankumar-s]

Description

Adds a keyboard shortcut to replay the onboarding tour after it has been dismissed or completed.

Users can press T after uploading a video to restart the onboarding tour from the first step. The shortcut has also been added to the Keyboard Shortcuts panel for discoverability.

Changes

• Added T shortcut to replay the onboarding tour
• Resets the tour back to the first step
• Clears the completed onboarding state when replaying
• Added "Replay onboarding tour" to the Keyboard Shortcuts panel
• Prevents the shortcut from triggering while typing in input fields

Related Issue

Closes #1785

Type of Contribution

• Bug fix
• New feature
• Documentation update
• Refactor
• GSSoC contribution

Participant Info

• GitHub username: @Jeevankumar-s
• Contribution level (Beginner/Intermediate/Advanced): Beginner

Checklist

• I have read the contribution guidelines
• My changes follow the project structure
• I have tested my changes in Chrome, Firefox, and Safari
• bun run lint passes (no ESLint errors)
• bunx tsc --noEmit passes (no TypeScript errors)
• New interactive elements have aria-label / accessible names
• No console.log statements left in
• This PR is related to a valid issue
• Screen recording attached above (required for UI/feature/design changes)

[netlify]

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[github-actions]

👋 Thanks for your PR, @Jeevankumar-s!

Welcome to Reframe — a browser-based video editor built for everyone 🎬

🟠 GSSoC'26 PR detected — thanks for contributing under GirlScript Summer of Code 2026!

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Quick checklist

• PR title follows Conventional Commits (e.g. feat: add dark mode)
• Linked the issue this PR closes (e.g. Closes #123)
• Tested the changes locally (bun run dev)
• Build passes (bun run build)

Useful links

• 📖 CONTRIBUTING.md
• 🐛 Open Issues
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Happy coding! 🎉

[github-actions]

✅ PR Format Check Passed — @Jeevankumar-s

Basic format checks passed. A maintainer will review your code changes.

This does not mean the PR is approved — it just means the format is correct.