feat(01-03): add make:plugin and plugin:add scaffolding

- Scaffold a compiling vendor.plugin module with go.mod, plugin.go and config/
- Register the module once in summer.yaml, go.work and the app go.mod
- Keep summer build on the same generate-and-compile path and print elapsed time

cmd/summer/main_test.go

@@ -1,15 +1,41 @@
 package main
 
 import (
+	"bytes"
 	"go/parser"
 	"go/token"
 	"os"
 	"path/filepath"
+	"slices"
 	"strconv"
 	"strings"
 	"testing"
+
+	"git.golem15.com/golem15/summercms/bonfire"
 )
 
+func TestToolCommandNames(t *testing.T) {
+	var names []string
+	for _, c := range toolCommands() {
+		names = append(names, c.Name)
+	}
+	for _, want := range []string{"build", "make:plugin", "plugin:add"} {
+		if !slices.Contains(names, want) {
+			t.Fatalf("missing %s in %v", want, names)
+		}
+	}
+
+	var buf bytes.Buffer
+	root := bonfire.NewRoot("summer", toolCommands(), &buf)
+	root.SetArgs([]string{"make:plugin", "--help"})
+	if err := root.Execute(); err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(buf.String(), "vendor.plugin") {
+		t.Fatalf("make:plugin help missing argument text:\n%s", buf.String())
+	}
+}
+
 func TestToolDoesNotImportExamplePlugins(t *testing.T) {
 	roots := []string{".", filepath.Join("..", "..", "internal", "build")}
 	fset := token.NewFileSet()