admin-config-render

Understand and safely change how the Decap /admin config is built — the gem-shipped admin machinery, the build-time render hook, the site-owned collections seam, the window.CMS_* identity injection, and the base_collections opt-out. Use when editing theme/admin/* (config.base.yml, the JS/HTML shells, the reviews dashboards), changing the render hook or its CLI mirror, debugging why /admin renders wrong/missing collections or wrong identity, adding a per-site collection, or hiding the platform's built-in collections. Trigger on mentions of "admin config", "config.base.yml", "render-decap-config", "decap_config_hook", "collections.site.yml", "base_collections", "CMS_REPO / window.CMS_*", or "/admin shows the wrong collections".