Backstage plugin builder

Plan and build Backstage plugin work by routing the request to the correct plugin type, validating current official guidance, producing the smallest useful implementation slice, and reporting the checks needed before integration or publication.

When to invoke

• "Plan a custom Backstage plugin for this app."
• "Scaffold a Backstage backend module for an extension point."
• "Add a catalog processor or scaffolder action."
• "Validate this Backstage plugin before publication."
• "Write a plugin ADR and architecture plan."

Inputs

Collect only missing facts. If intent is already clear, proceed.