- ContentType, ContentTypeForController, Records and MatchPath on the
registry; the pure MatchPattern for whole-segment placeholder matching
- two types declaring the same Content.Model or Controller stop the boot
- TestContent* cover lookups, optional Records, boot errors, MatchPattern
and MatchPath precedence (first exact, else first inexact)
- docs: Content descriptors in menu-item-types.md, signpost README
