TODOs

List of code things that need adding to Thunderhorse core.

• [ ] PAGI lifespan hooks need to be forwarded to nested PAGI apps: https://github.com/jjn1056/pagi/issues/22
• [ ] Router should be sealed when application starts, to prevent adding more routes at runtime and invalidating cache
• [ ] Modules should be able to provide a list of modules they depend on, and be loaded after them
• [ ] Modules should allow adding methods to more than just controllers (request, response, sse and websocket at least)
• [ ] Thunderhorse::API, minimal JSON Schema-powered, OpenAPI-aware overlay for Thunderhorse (in core or separate module)