[Task](greenhouse): Create standalone template app for external plugin development

[ArtieReus]

Task Description

Prepare the template app to be fully standalone and create tooling that enables external developers to easily bootstrap their plugin development using the template as a base.

Sub-tasks

• Convert template app to be fully standalone (runnable outside the monorepo)
• Ensure template app includes all necessary dependencies and configuration
• Create a script or skill that allows external developers to clone the standalone template app
• Document the plugin development workflow for external developers
• Add setup and testing instructions
• Test that standalone template can be cloned and run independently
• Create a README for external developers with getting started guide

Related Issues

• Epic: [EPIC](greenhouse): Dynamic External Plugin Integration System #1624

Additional Context

This task provides the foundation for external plugin development by creating a ready-to-use template that external developers can clone and use as their starting point. The template should be completely independent of the Juno monorepo and include clear documentation for developers unfamiliar with the project structure.