pozylon pushed a major “Refactor Plugin System” update on master, introducing Unchained Engine v5.0 breaking changes. The plugin architecture is modernized to explicit, side‑effect‑free registration via a new PluginRegistry (and preset register* functions), with examples and presets updated accordingly; deprecated GraphQL order mutations/fields and router aliases were removed, and the PayPal Checkout plugin was dropped due to a deprecated SDK. This also adds framework-agnostic plugin route mounting (Express/Fastify via @whatwg-node/server), improves OIDC token verification by switching to jose + JWKS, and updates migration/changelog docs and test scripts to match the new setup.