cratefield-ui

What it is

cratefield-ui.

Mount it on the builder and every module that declares a surface gets pages at /ui/<module>/<action>, the same markup as a fragment with ?fragment=1, landing pages at /ui/<module>/<action>/{done,expired}, and the base stylesheet at /ui/cf.css. Nothing is written twice: the pages are generated from the types the handler already accepts.

Modules stay JSON-only. A form posts to its own /ui route; the handler turns the form into the JSON the module accepts and dispatches it in-process to the /v1 router, then renders a 202 as a notice, a problem+json as the form with the error on its own field, and passes a 303 to the browser. Styling is a CSS contract rather than an API: cf-* classes and data-cf-* attributes, no shadow DOM, and cf.css inside @layer cf written against --cf-* custom properties, so a venture stylesheet wins without !important.