Jazz Loading and Subscriptions

This skill is for correctness of what is loaded, when it is loaded, and how updates stay observable.

Scope

• Resolve query design (resolve, $each, $onError)
• $isLoaded and loadingState handling
• ensureLoaded() semantics (returns a copy at requested depth)
• Manual and framework subscriptions
• Startup/reconnect race prevention
• Union narrowing constraints for ensureLoaded and subscribe

Non-Negotiable Rules

• Treat shallow and deep loading as explicit architecture decisions.
• Use $each only when immediate full collection hydration is required.
• Handle loading states intentionally: loading, loaded, unavailable, unauthorized, and post-delete deleted flows.
• Always teardown manual subscriptions.