4.15.4

(fix): Fix cross-reference links in C++ library documentation. Entity pages now use relative links resolved via an entity registry, template specializations link to their dedicated pages on index pages, namespace index links are properly slugified, and operator method anchors use deterministic safe names to avoid collisions.

4.15.3

(fix): Fix fern generator upgrade failing with ENOENT on package.json when multiple CLI processes run concurrently (e.g., in parallel tests). A cross-process file lock now serializes npm installs to the shared ~/.fern/migration-cache prefix, preventing concurrent install races.