feat(cli)!: use giget 0.1x with template registry for nuxi init

[pi0]

🔗 Linked issue

#7361

❓ Type of change

• 📖 Documentation (updates to the documentation or readme)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

This PR upgrades to unjs/giget 0.1.x with custom template registry support. This way we can have beautiful aliases for template names without rebuilding and releasing nuxi CLI but directly from nuxt/starter. A custom environment variable NUXI_INIT_REGISTRY can be used to use an alternative registry.

Breaking change: Usage of -t repo/name is changed to -t gh:repo/name for 3rd party templates.

DX change: Using more minimal output now:

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

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[pi0]

(merging to try on edge and also unblock #7383)

[danielroe]

@pi0 Could we avoid a breaking change? Often npx nuxi does not run the latest version of nuxi owing to npm caching so we will likely need to update documentation to npx nuxi@latest if we are providing a template option, which seems a bit verbose...

Edit - oh, I see - only breaking for non-nuxt starter templates. 👍

[pi0]

Indeed actually we could also not break the org/name usage and allow without gh: prefix but i thought it would be too implicit and making it fragile for future development with registry (example: supporting registry templates with slash in their name like. we don't know it is registry id or gh id)