With the library group disabled the entries stay unreadable and unwritable, but
page outline, node-get and render summary still name global module IDs; full
hiding follows in 3b.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
A library entry as source now requires LibraryAccess::canInsert() (add_library,
writable library group) and follows lit-library-insert's Tools-tab state
(disabled -> unsupported). DiviPageLoader::library() gets its caller.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>