feat: PWA Offline Support Implemented

[BhelPuriPanda]

Add Progressive Web App (PWA) support

This PR adds full Progressive Web App support to Reframe while maintaining compatibility with output: "export" static builds.

Features Added

Web App Manifest

• Added public/manifest.json
• Configured standalone display mode
• Added theme/background colors
• Added installable app icons (192x192, 512x512)
• Added screenshots for install previews

Service Worker

Added a custom public/sw.js service worker with:

• precaching for core app shell assets
• network-first caching for navigational HTML requests
• cache-first caching for static assets (JS, CSS, WASM, media)
• runtime caching for FFmpeg WASM assets loaded from jsdelivr CDN
• offline fallback support for / and /index.html

Install UX

• Added InstallButton.tsx
• Implemented deferred beforeinstallprompt handling
• Added manual install flow through a header install button
• Automatically hides install UI after successful installation

Header/Layout Fixes

• Moved the "Star on GitHub" button into the sticky header
• Fixed overlap issues affecting the install button and theme toggle
• Registered manifest/theme metadata through the Next.js Metadata API

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Verification

Build Verification

bun run build

Build/export completes successfully with no regressions.

Manual Testing

Verified:

• service worker registration
• manifest detection
• installability on Chrome/Edge
• offline app shell loading
• FFmpeg asset caching
• standalone app launch behavior

Offline Verification

After first load, the application continues to function offline, including cached FFmpeg WASM resources required for browser-side video processing.

Reframe.Browser-based.Video.Editor.-.Reframe.Resize.trim.and.export.videos.in.your.browser.2026-05-22.14-03-21.mp4

A screen recording demonstrating installation flow and offline functionality is included with this PR.

Closes #663

[vercel]

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[github-actions]

👋 Thanks for your PR, @BhelPuriPanda!

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

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 — @BhelPuriPanda

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.

[BhelPuriPanda]

Hi @magic-peach, kindly review my PR I have tested it locally, and it works fine, and all checks passed. For the install button, it is there for those who haven't installed yet. When installed, you only see the open in App in the URL bar, like in YouTube. I have shown in the recording that it works offline as well.