feat(diary): boot --help invocations with the console at warn (quick-261028-rqc)

- Options.Args holds the command-line arguments; FromGlobals fills it
  from os.Args[1:], so the generated main needs no change
- Bootstrap and Setup install the setup with Quiet when Args only ask
  for help (-h, --help) and no -v is given; files keep their levels
- TestBootQuietSmoke runs the generated main's sequence with a plugin
  that logs from Register and Boot

modules/diary/diary.go

@@ -31,6 +31,8 @@ type Options struct {
 	// to debug; 3 or more also adds source locations on the console.
 	Verbosity int
 	// Quiet raises the console channels to warn; files keep their levels.
+	// Bootstrap and Setup also set it for arguments that only ask for help
+	// (see Args).
 	Quiet bool
 	// Color decides on styled console output (bonfire.ColorAuto by default).
 	Color consolekit.ColorMode
@@ -43,6 +45,14 @@ type Options struct {
 	Environ []string
 	// Now is the clock of the daily writers; nil means time.Now.
 	Now func() time.Time
+	// Args are the command-line arguments without the program name. When
+	// non-nil, Bootstrap and Setup check whether they only ask for help
+	// and, at verbosity 0, install the setup with Quiet, so the records
+	// plugins log while they register and boot stay off the console.
+	// FromGlobals sets them to a copy of os.Args[1:]; nil (an Options
+	// literal) means no check. A caller that dispatches on other arguments
+	// sets Args itself.
+	Args []string
 }
 
 func (o Options) normalize() Options {
@@ -116,13 +126,15 @@ func For(component string) *slog.Logger {
 
 // Bootstrap installs a console channel on w, before configuration is read,
 // and makes diary the process default logger. The generated main calls it
-// first; Setup replaces it once config/log.yaml is loaded.
+// first; Setup replaces it once config/log.yaml is loaded. Like Setup, it
+// starts the console at warn when opts.Args only ask for help and no -v is
+// given.
 func Bootstrap(w io.Writer, opts Options) {
 	if w == nil {
 		w = os.Stderr
 	}
 	opts.Stderr = w
-	opts = opts.normalize()
+	opts = bootQuiet(opts.normalize())
 	cfg := DefaultConfig()
 	cfg.Default = "console"
 	cfg.Channels = map[string]ChannelConfig{"console": {Driver: DriverConsole, Format: FormatAuto}}
@@ -138,13 +150,14 @@ func Bootstrap(w io.Writer, opts Options) {
 // Setup parses log.* from cfg (ParseConfig), builds the channels and makes
 // them the target of every diary logger and of the process default logger.
 // A configuration error is returned and leaves the previous setup in place;
-// a daily file that cannot be opened never fails Setup.
+// a daily file that cannot be opened never fails Setup. When opts.Args only
+// ask for help and no -v is given, the console channels start at warn.
 func Setup(cfg *compass.Config, opts Options) error {
 	conf, err := ParseConfig(cfg)
 	if err != nil {
 		return err
 	}
-	opts = opts.normalize()
+	opts = bootQuiet(opts.normalize())
 	ch, err := buildChannels(conf, opts)
 	if err != nil {
 		return err
@@ -215,9 +228,15 @@ func setVerbosityLocked(v int, quiet bool) {
 // FromGlobals returns the Options for the console global options: their
 // verbosity, quiet switch and color mode. The generated main passes it to
 // Bootstrap and Setup. g is a bonfire.Globals: bonfire and diary share the
-// type through internal/consolekit, so diary does not link bonfire.
+// type through internal/consolekit, so diary does not link bonfire. It also
+// sets Args to a copy of os.Args[1:] (empty, not nil, without arguments), so
+// an invocation that only asks for help boots with the console at warn.
 func FromGlobals(g consolekit.Globals) Options {
-	return Options{Verbosity: g.Verbosity, Quiet: g.Quiet, Color: g.Color}
+	args := []string{}
+	if len(os.Args) > 1 {
+		args = append(args, os.Args[1:]...)
+	}
+	return Options{Verbosity: g.Verbosity, Quiet: g.Quiet, Color: g.Color, Args: args}
 }
 
 // ApplyGlobals applies the parsed global options to the installed setup: