Give -v to verbose, move --version to -V (closes #64)

urfave/cli's built-in version flag claimed -v, so "mfer -v --version"
failed to parse, and -v meant version at the root but verbose on
generate, check, freshen and fetch. Verbose is the more common meaning,
so the root now takes -v and -q too, and the version flag takes -V. A
-v or -q before generate, check, freshen, fetch or export applies to
that subcommand; list keeps its fixed quiet logging.

User-visible changes: -v no longer prints the version; use -V or
--version. "mfer version" prints "mfer version 0.1.0 (...)", the same
line as --version, instead of the bare "0.1.0 (...)".

Tests: runCLI now points the logger at io.Discard after each run, so
other tests' log lines cannot land in a finished run's output.

Model: opus-4-8 (implementation); opus-5-5 (rework)

internal/cli/mfer.go

@@ -19,6 +19,7 @@ const (
 	cmdCheck    = "check"
 	cmdExport   = "export"
 	cmdFetch    = "fetch"
+	cmdVersion  = "version"
 
 	flagProgress = "progress"
 
@@ -68,6 +69,12 @@ func (mfa *CLIApp) VersionString() string {
 	return mfer.Version
 }
 
+// printVersion writes the version line shared by the --version flag and the
+// version subcommand, so both produce identical output.
+func (mfa *CLIApp) printVersion() {
+	_, _ = fmt.Fprintf(mfa.Stdout, "%s version %s\n", mfa.appname, mfa.VersionString())
+}
+
 func (mfa *CLIApp) printBanner() {
 	if log.GetLevel() <= log.InfoLevel {
 		_, _ = fmt.Fprintln(mfa.Stdout, banner)
@@ -78,20 +85,34 @@ func (mfa *CLIApp) printBanner() {
 	}
 }
 
+// setVerbosity sets the log level from -v and -q, given before the subcommand
+// name (the root's copies), after it (the subcommand's own copies), or both.
+// urfave/cli reads a flag from the nearest command that defines it, so each
+// command in the lineage is asked. The highest -v count wins rather than the
+// sum, because a subcommand without its own copies reads the root's.
 func (mfa *CLIApp) setVerbosity(c *cli.Context) {
 	_, present := os.LookupEnv("MFER_DEBUG")
 
+	verbosity := 0
+	quiet := false
+
+	for _, ctx := range c.Lineage() {
+		verbosity = max(verbosity, ctx.Count("verbose"))
+		quiet = quiet || ctx.Bool("quiet")
+	}
+
 	switch {
 	case present:
 		log.EnableDebugLogging()
-	case c.Bool("quiet"):
+	case quiet:
 		log.SetLevel(log.ErrorLevel)
 	default:
-		log.SetLevelFromVerbosity(c.Count("verbose"))
+		log.SetLevelFromVerbosity(verbosity)
 	}
 }
 
-// commonFlags returns the flags shared by most commands (-v, -q)
+// commonFlags returns the -v and -q flags taken by the root and by the
+// generate, check, freshen and fetch subcommands.
 func commonFlags() []cli.Flag {
 	return []cli.Flag{
 		&cli.BoolFlag{
@@ -259,6 +280,8 @@ func (mfa *CLIApp) exportCommand() *cli.Command {
 		Usage:     "Export manifest contents as JSON",
 		ArgsUsage: "[manifest file or URL]",
 		Action: func(c *cli.Context) error {
+			mfa.setVerbosity(c)
+
 			return mfa.exportManifestOperation(c)
 		},
 	}
@@ -266,10 +289,10 @@ func (mfa *CLIApp) exportCommand() *cli.Command {
 
 func (mfa *CLIApp) versionCommand() *cli.Command {
 	return &cli.Command{
-		Name:  "version",
+		Name:  cmdVersion,
 		Usage: "Show version",
 		Action: func(_ *cli.Context) error {
-			_, _ = fmt.Fprintln(mfa.Stdout, mfa.VersionString())
+			mfa.printVersion()
 
 			return nil
 		},
@@ -325,6 +348,21 @@ func (mfa *CLIApp) run(args []string) {
 	log.SetOutput(mfa.Stdout, mfa.Stderr)
 	log.Init()
 
+	// -v means verbose, not version. urfave/cli's built-in version flag
+	// claims -v by default, which made "mfer -v --version" fail to parse and
+	// gave -v a different meaning at the root than on the generate, check,
+	// freshen and fetch subcommands, where it means verbose. Verbose is the
+	// more common meaning of -v in tools that offer both, so -v means verbose
+	// at the root too and the version flag takes the capital -V.
+	// VersionFlag and VersionPrinter are urfave/cli package globals; run() is
+	// serialized in tests, so assigning them here is safe.
+	cli.VersionFlag = &cli.BoolFlag{
+		Name:    cmdVersion,
+		Aliases: []string{"V"},
+		Usage:   "print the version",
+	}
+	cli.VersionPrinter = func(_ *cli.Context) { mfa.printVersion() }
+
 	mfa.app = &cli.App{
 		Name:                 mfa.appname,
 		Usage:                "Manifest generator",
@@ -332,11 +370,13 @@ func (mfa *CLIApp) run(args []string) {
 		EnableBashCompletion: true,
 		Writer:               mfa.Stdout,
 		ErrWriter:            mfa.Stderr,
+		Flags:                commonFlags(),
 		Action: func(c *cli.Context) error {
 			if c.Args().Len() > 0 {
 				return fmt.Errorf("%w %q", errUnknownCommand, c.Args().First())
 			}
 
+			mfa.setVerbosity(c)
 			mfa.printBanner()
 
 			return cli.ShowAppHelp(c)