A comprehensive JAM stack reference app with offline-first architecture, service worker batching, and multi-user conflict resolution

I've been working on a practical reference project for building modern web applications that demonstrates some patterns I rarely see documented well together:

• Service worker-first architecture (not just PWA features)
• Offline data mutation batching with IndexedDB staging
• Multi-user optimistic concurrency control with 3-way merge
• Sophisticated testing with Docker Testcontainers + multi-layer coverage
• Hand-crafted vanilla JS (no framework dependencies)

The project focuses on being a learning resource rather than another framework. Everything is built to be readable and educational.

https://github.com/localnerve/jam-build

Would love feedback from other developers who've tackled similar offline-first challenges!