d7f5dc83f8
Replace legacy global BackendRegistry with bootstrap context adapter that maintains backward compatibility while delegating to explicit context. Changes: - Create BOOTSTRAP_CONTEXT: OnceLock<Arc<Mutex<RegistrationContext>>> - register_backend(): delegates to bootstrap context - is_backend_registered(): reads from bootstrap context - registered_backends(): reads from bootstrap context - build_rig(): reads from bootstrap context Result: Plugins continue calling global functions, but all operations now route through the bootstrap context instead of a separate global registry. This completes the de-globalization while maintaining full backward compatibility with existing plugins. Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com> Signed-off-by: Stanislaw Grams <stanislawgrams@gmail.com>