* feat(ffi): add retained callbacks - Add format 4 retained registration and explicit release descriptors with pointer-identity validation. - Pin callbacks in runtime registration tables and emit matching C/LLVM adapters with deferred exception checks. - Cover lifecycle and sanitizer cases, and document the same-thread callback boundary. Co-authored-by: DemonGPT <127974011+DemonGPT@users.noreply.github.com> * fix(ffi): harden retained callback lifecycle * fix(ffi): reject same-call retained releases * fix(ffi): reject inline retained releases * fix(ffi): preserve plain exit listener timing --------- Co-authored-by: DemonGPT <127974011+DemonGPT@users.noreply.github.com>
- Retain representative Darwin kqueue coverage in the default gate. - Schedule native runtime tests by host and make Linux clang invocations portable. - Resolve canonical OCI manifest digests for direct and indexed images.
