fix(ax): AX compliance sweep — banned imports, naming, test coverage
- pkg/api/provider.go: remove banned os/syscall imports; delegate to
new process.KillPID and process.IsPIDAlive exported helpers
- service.go: rename `sr` → `startResult`; add KillPID/IsPIDAlive exports
- runner.go: rename `aggResult` → `aggregate` in all three RunXxx methods;
add usage-example comments on all exported functions
- process.go: replace prose doc-comments with usage-example comments
- buffer.go, registry.go, health.go: replace prose comments with examples
- buffer_test.go: rename TestRingBuffer_Basics_Good → TestBuffer_{Write,String,Reset}_{Good,Bad,Ugly}
- All test files: add missing _Bad and _Ugly variants for all functions
(daemon, health, pidfile, registry, runner, process, program, exec, pkg/api)
Co-Authored-By: Virgil <virgil@lethean.io>
861c88b8e8