feat: enhance export workflow and progress UI

[TwilightDawn7]

Description

Enhanced the export progress experience by improving visual feedback, workflow clarity, and responsiveness during video processing.

Changes made:

• Added smoother export progress transitions
• Improved workflow stage visualization (Preparing → Processing → Finalizing → Complete)
• Added dynamic processing states/messages
• Improved progress percentage and ETA placement
• Added animated processing orbit loader
• Added rotating informational tips
• Improved spacing and alignment across export components
• Unified styling between progress indicators and workflow stages
• Improved theme responsiveness and visual consistency
• Added accessibility improvements for export status updates

Related Issue

Closes #911

Type of Contribution

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

Participant Info

• GitHub username: TwilightDawn7
• Contribution level (Beginner/Intermediate/Advanced): Advanced

Screen Recording

screen_recording.mp4

Mobile Responsiveness recording

mobile_responsiveness.mp4

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]

@TwilightDawn7 is attempting to deploy a commit to the magic-peach1's projects Team on Vercel.

A member of the Team first needs to authorize it.

[github-actions]

👋 Thanks for your PR, @TwilightDawn7!

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 — @TwilightDawn7

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.

[vercel]

Deployment failed with the following error:

The provided GitHub repository does not contain the requested branch or commit reference. Please ensure the repository is not empty.

[magic-peach]

@TwilightDawn7 the deployment is failing please fix

[magic-peach]

@TwilightDawn7 please resolve the conflicts

[TwilightDawn7]

@TwilightDawn7 please resolve the conflicts

ok i will try to fix this.