feat: Vue adapter package (loadgo-vue)

[franverona]

Summary

Add a loadgo-vue package providing an idiomatic Vue API over the existing vanilla JS core via a composable.

Motivation

The vanilla JS implementation works in Vue via onMounted/onUnmounted, but users have to manually handle init/destroy lifecycle. A composable removes that boilerplate.

Proposed API

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

Notes

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