Objective

Implement the foundational Proxy classes for the new data loading architecture.

Tasks

1. src/data/proxy/Base.mjs:

   • Abstract base class.
   • Should define the interface for read(operation) (or similar).
   • Should handle basic URL configuration.

2. src/data/proxy/Stream.mjs:

   • Extends Base.
   • Uses fetch to retrieve the resource.
   • Implements the NDJSONStream parsing logic (using TransformStream and TextDecoderStream).
   • Should expose a way to yield records incrementally (e.g., via events or a generator).

Requirements

• Must work in the App Worker (and potentially SharedWorker).
• Must handle JSONL (newline-delimited JSON).
• Error handling for network failures and parse errors.