Service worker runtime

[mfulton26]

Goals

1. Power offline web applications
2. More than just statically cached pages but dynamic, server components served while offline
3. Caching assets in browser Cache API

Non-Goals

1. Syncing data back to the server (that's up to app developers)

Background

Create React App could be used offline but modern React frameworks don't support this use case yet.

Proposal

Most of the edge runtime code is already service worker compatible. Some things might need to change (no top-level await, no dynamic import, no Node.js specific API usage).

I'd like to contribute but could use some pointers on where service either fetch event handler would best hook into a compiled Next app, etc.

[mfulton26]

Related: #63663