Review what's missing to bring "Offline Scan" to prime time

[teolemon]

What

• Offline scan is still hidden in devmode
• From memory, one of the issues was that some queries to download offline products were timing out. However I've tested a bunch of them that are slow but work
• We need to review and make a list here on what's still on our plate to ship this feature.

Blocking points

Beta Give feedback

1. Get the server to ship scalable downloads
2. Make the Offline section visible in the settings (toggling it off by a dev mode switch until we launch)
3. Create an onboarding screen/pipeline dedicated to offline (as a bottom sheet?)

References

• 📶 🤳 Offline scanning (Tracker) #18
• https://github.com/openfoodfacts/smooth-app/labels/offline%20browsing
• Feel free to close old bugs as you synthesize what's left in them