square/dagger ? reverse-engineered prompt

Build me a small Java library for dependency injection that works well for Android and plain Java apps.

I want it to let me define objects and their dependencies with annotations, then generate the wiring code at build time so the app can create everything automatically. It should include a runtime library plus a compiler module that generates the injector code, and it should be easy to add to a Maven project. Please also include a few simple examples that show how to use it in a real app, like creating services, activities, and app level objects.

Keep it fast and lightweight, and make sure the generated code is clean and usable without extra setup. If you need to, look up current docs online for any missing details about how this style of dependency injection is usually wired together.