Add a Workfront UI-extension skill suite to the app-builder plugin

[vahagnkostandyan]

Problem

The app-builder plugin currently offers only generic scaffolder skills
(appbuilder-ui-scaffolder, appbuilder-action-scaffolder, appbuilder-project-init,
etc.). None of them cover building customized Workfront UIs on Adobe App Builder —
specifically:

• Workfront UI extension points and the React/Spectrum SPA that targets them
• The Workfront Public API v21 from serverless Runtime actions
• Planning (Maestro) API access, which must go through the Workfront MCP
• Previewing an in-development build inside Workfront

Practitioners building Workfront extensions have to assemble this from generic
App Builder material and repeatedly hit the same gotchas — e.g. constructing the
deployed-app Experience Cloud shell URL.

Proposed solution

Add a Workfront-focused skill suite to the app-builder plugin, grouped under a new
umbrella skill that routes each stage of the workflow (orient → scaffold → build →
test → deploy → publish):

• appbuilder-workfront — umbrella/router, with shared troubleshooting + commands references
• workfront-ui-extension — front-end SPA + Workfront extension points
• workfront-actions — Runtime actions + Workfront Public API v21
• workfront-local-testing — previewing a build inside Workfront

Plus an end-to-end USAGE.md practitioner guide, evals/ for each skill, example
assets, and cross-links to the existing generic scaffolder skills.

Value

Gives agents a guided, discoverable path for Workfront UI-extension work and captures
the non-obvious gotchas up front, instead of leaving them to be rediscovered per project.