Dependency injection

Status: Superseded by ADR-0017 and ADR-0020 (2026-09-14)

Context: Apps compose a dozen components with lifecycles.

Options: Fx (runtime reflection), Wire (compile-time codegen, archived 2025), custom container, manual constructor injection.

Decision: Manual constructor injection in one owned app.go, plus app.Run with Starter/Stopper interfaces.

Why: Zero magic, compile-time errors, readable by every Go developer and AI tool. The generator writes the boring part, which was the only real argument for a container.

Tradeoffs: app.go grows in large apps (acceptable; can be split by hand).

Consequences: Modules must accept dependencies as parameters, never look them up globally.