Add a `logos_protocol_shared` target that builds the same sources as a
shared library (liblogos_protocol.{so,dylib}), exporting the
language-neutral lp_* C ABI for out-of-plugin callers that bind it at
runtime via dlopen/FFI (logos-js-sdk's koffi.load, logos-rust-sdk's
callerBuildSupport) — the role liblogos_module_client previously filled.
The static `logos_protocol` archive and its EXPORT set are untouched, so
in-plugin code and find_package(logos-protocol) are unaffected; the shared
target is deliberately not exported into the CMake package.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
