Offline Support & File Caching (PWA)

[LiukScot]

Summary

Allow the app to work offline and keep downloaded content available on mobile (including iOS).

Tasks

• Service Worker with Workbox for caching app shell and static assets
• Cache API responses (pages list, page content, blocks) for offline reading
• IndexedDB local store for pages and blocks (offline-first architecture)
• Sync queue: edits made offline are queued and synced when back online
• Conflict resolution strategy (last-write-wins or merge)
• PWA manifest with icons, splash screens, display: standalone
• iOS-specific meta tags (apple-mobile-web-app-capable, status bar style)
• Background sync for pending changes
• Visual indicator showing online/offline status and pending sync count
• File/attachment caching for offline access to uploaded media

Notes

iOS Safari supports Service Workers and Cache API but has storage limits (~50MB per origin) and may evict after 7 days of inactivity. Consider prompting users to open the app periodically or using the Storage API to request persistent storage.