feat: React adapter package (loadgo-react)

[franverona]

Summary

Add a loadgo-react package providing an idiomatic React API over the existing vanilla JS core.

Motivation

The vanilla JS implementation already works in React via useEffect/useRef, but users have to manually handle init/destroy lifecycle and cleanup. A dedicated hook removes that boilerplate.

Proposed API

// Hook
const { setprogress, getprogress, resetprogress, loop, stop } = useLoadgo(ref, options)

// Optionally a component wrapper
<LoadgoImage src="..." progress={42} options={...} />

Notes

• Thin adapter over loadgo-vanilla.js — no reimplementation of core logic
• react and loadgo (vanilla) as peer dependencies
• Publish as a separate loadgo-react npm package
• Depends on monorepo restructure: chore: convert project to npm workspaces monorepo #27