Automatically implements LiveVue.Encoder for resources using the Alva.Resource extension.

The generated implementation encodes exactly the resource's public fields (attributes, calculations, relationships and aggregates, as resolved by Alva.Registry.public_fields/1) and then re-encodes recursively, so nested Ash.NotLoaded/Ash.ForbiddenField/Ecto.Schema.Metadata values fall through to the default implementations in Alva.LiveView.Encoders. Internal struct fields (__metadata__, __meta__, __order__, ...) never cross the Vue boundary.

The implementation module is created with Module.create/3 and deliberately avoids any compile-time reference to the resource struct (no struct pattern), so it does not need to wait for the struct to be finalized. It also must not run in the after_compile?/after_verify phase: creating a module while the code server holds the verification lock deadlocks the parallel compiler.

A manually defined implementation (either defimpl or Protocol.derive in the host app) always wins and prevents the automatic derive.