UI.23 Layout designer page in the developer section: how to build your own layout theme with the CadCraft icons, with the icon gallery and a layout checker

Owner 2026-11-09: "there should be a designer page, in the developer section, where people learn how to build their own layout theme with our icons." Today /developers is the API only (Overview, Guides, Reference, Console, Changelog, Your keys); layouts are documented for makers in the add-ons repo (docs/LAYOUTS.md) and the help topic common/layout-own, and nothing shows the icons. Change: /developers/layouts (SSR from Catalog and the library data, sub-nav entry "Layouts", in the sitemap and llms.txt): (1) the pattern: the zone map and the dockable-unit rule from UI.1 drawn live (the mockup's dock manager moved onto the site as a component), the block presets, what an adapter fills per app; (2) the icon gallery from the UI.22 build: every icon in Full colour, Outline colorized and the app's theme colour, with key, name and the commands that use it, search, copy-the-key, and the UI.13 drawing rules for anyone adding one; (3) the step-by-step guide: start from a built-in file, place units in zones, choose tool rows and their icons (toolrows.icons "set"), set the tone (UI.16), save as <name>.ccworkspace.json, install it in Settings › Layout › Add a layout file or in SuperCad Studio, or publish it as a layout add-on for everyone; (4) a layout checker: drop a layout file and the page runs the shared format module's resolveLayout in the browser (the engine's own code; progressive enhancement, the guide reads without it) and lists the notes: unknown places, blocks an app cannot fill, missing icon keys; (5) "Design it in the app": opens any app in /use in Arrange mode (UI.5) with one-click export of the result, so the page teaches and the app does; (6) "Themes people made": layout add-ons from the add-ons index, none until there are some. Words in en, es-MX, id; common/layout-own links the page; the 0.10 release note names it. Public and indexable; names no other program (vendor-names rule).