feat: theme toggle

[Palakchoithani]

Description

Added theme-related UI support and persistence behavior, improved export readability in dark mode and high-contrast mode, fixed the onboarding tour crash, and cleaned up lint/typecheck issues in the branch.

Related Issue

Closes #928

Type of Contribution

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

Participant Info

• GitHub username: Palakchoithani
• Contribution level (Beginner/Intermediate/Advanced): Intermediate

Screen Recording

596754167-e9c370fa-7463-4f8c-b949-6ed6cc0090ef.mov

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)

[vercel]

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[github-actions]

👋 Thanks for your PR, @Palakchoithani!

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

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

What happens next

1. 🤖 Automated checks — build & TypeScript typecheck will run automatically
2. ✅ Vercel preview — a preview deployment will be created (requires maintainer authorization for fork PRs)
3. 👀 Code review — a maintainer will review your changes
4. 🚀 Merge — once approved, your PR will be merged!

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
• ⭐ Star the repo to support the project!

Happy coding! 🎉

[github-actions]

✅ PR Format Check Passed — @Palakchoithani

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.

[Palakchoithani]

This PR adds theme support and improves accessibility across the export flow.

What changed:

• Added theme toggle support with persistence.
• Improved export UI readability in dark mode.
• Fixed export button visibility in high-contrast mode.
• Softened the high-contrast export button color so it is easier on the eyes.
• Fixed the onboarding tour crash caused by a missing step position.
• Cleaned up lint and TypeScript issues, including warning-prone image usage and a missing keyboard shortcut dependency.

Validation:

• bun run lint passes
• bunx tsc --noEmit passes

Thanks for reviewing.

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