Hi @aki59, thanks for the question!

The issue is a YAML formatting bug in your preset.yml. Each property is written as a separate list item (- key: value), but they need to be keys of the same dict — only the first property gets the -:

What you have (incorrect):

provides:
  templates:
    - type: "template"
    - name: "constitution-template"
    - file: "templates/comptest-constitution.md"
    - strategy: "prepend"

YAML reads this as four separate objects, each with a single key — so none of them have type, name, and file together, which is required.

What you need:

provides:
  templates:
    - type: "template"
      name: "constitution-template"
      file: "templates/comptest-constitution.md"
      strategy: "prepend"

Once that's fixed, your constitution content will prepend correctly to the core template.

Regarding the folder structure not appearing in the plan: the prepend strategy gives the AI agent your text as context, but how faithfully it reproduces directory layouts depends on the model. With gpt-5-mini you may see it take liberties — try a larger model if the output still isn't matching your template after the YAML fix.