fx wrote its own steps of starting and stopping as plain text to
stderr. It now logs them with its slog event logger through the
backend's logger, so off a terminal every line the backend's own
logger and fx write is JSON. A malformed config file now makes
config.New return the error instead of panicking. A test runs the
server as a child process and checks that all it writes is JSON, on
a normal start and stop and with such a config file. The backend
logs its name, version and architecture once at start.
The health check's uptime keys are now uptime_seconds and
uptime_human; its type and method take the names
GO_HTTP_SERVER_CONVENTIONS.md gives.
Model: opus-5-5
