DerivedTypesEntryNode.Filter reported Recurse, but the cascade's
Recurse handling force-loads the entry's lazy children and hides the
entry when all of them are hidden. A leaf derived type has no children,
so every entry under "Derived Types" ended up hidden, and the hiding
propagated up the whole derived chain. The WPF tree showed these
entries as matches; Match restores that and also keeps the entries'
children lazy instead of eagerly scanning the assembly list for each
level of the chain.
Assisted-by: Claude:claude-fable-5:Claude Code
Christoph Wille