Compile typed command runners

builtins.go

@@ -30,16 +30,15 @@ type versionDocument struct {
 }
 
 func (a *App) installBuiltins() error {
-	help := NewCommand(CommandSpec[helpInput]{
+	help := captureCommand(CommandSpec[helpInput]{
 		Name:        "help",
 		Summary:     "Show help for commands.",
 		Description: "Describe registered commands and their inputs.",
 		Arguments: []Argument[helpInput]{RepeatArgument(ArgumentMeta{Name: "COMMAND", Usage: "registered command path"}, 0, -1,
 			func(value string) (string, error) { return value, nil },
 			func(input *helpInput, value Supplied[[]string]) { input.Targets = value })},
-		Run: func(invocation Invocation, input helpInput) Outcome {
-			return a.renderHelpTargets(input.Targets.Value, invocation.Streams)
-		},
+	}, func(current commandExecution, input helpInput) Outcome {
+		return current.renderHelpTargets(input.Targets.Value)
 	})
 	scopeDefault := "app"
 	formatDefault := "text"