feat(11.1-05): add the walkthrough's admin controller, publish command and published_at migration

- make:admin-controller, make:command and make:migration output, finished:
  the Posts controller serves models.Post behind acme.blog.access_posts,
  WinterCMS-style form and list YAML embedded through pact.AdminAssets,
  blog:publish sets published_at by slug with a bound parameter
- the posts route lists published posts only, newest first
- Docker tests migrate an ICU pl-PL database, roll back published_at, serve
  the route and run blog:publish with a published and an opened database
- the page gains the admin controller, console command and added-column
  sections

docs/examples/blog/routes.go

@@ -23,15 +23,16 @@ func (p *Plugin) Routes(r pact.Router) error {
 // postJSON is the response shape of one post. It is built field by field,
 // so a column added to the model never leaks into the API.
 type postJSON struct {
-	ID        uint      `json:"id"`
-	Title     string    `json:"title"`
-	Slug      string    `json:"slug"`
-	Body      string    `json:"body"`
-	CreatedAt wire.Time `json:"created_at"`
+	ID          uint      `json:"id"`
+	Title       string    `json:"title"`
+	Slug        string    `json:"slug"`
+	Body        string    `json:"body"`
+	PublishedAt wire.Time `json:"published_at"`
 }
 
 // listPosts answers GET /api/blog/posts?page=N&per_page=M with one page of
-// posts, newest first, in the {data, meta} shape of Laravel's paginator.
+// published posts, newest first, in the {data, meta} shape of Laravel's
+// paginator. Drafts, whose published_at is NULL, are never listed.
 func (p *Plugin) listPosts(w http.ResponseWriter, r *http.Request) {
 	db, ok := p.app.Lookup[*gorm.DB]()
 	if !ok {
@@ -41,25 +42,25 @@ func (p *Plugin) listPosts(w http.ResponseWriter, r *http.Request) {
 	page := queryInt(r, "page", 1, 1, 10000)
 	perPage := queryInt(r, "per_page", p.app.Config.Int("acme.blog.per_page"), 1, 100)
 
-	q := db.WithContext(r.Context()).Model(&models.Post{})
+	q := db.WithContext(r.Context()).Model(&models.Post{}).Where("published_at IS NOT NULL")
 	var total int64
 	if err := q.Count(&total).Error; err != nil {
 		wire.WriteOpaque500(w)
 		return
 	}
 	var posts []models.Post
-	if err := q.Order("created_at DESC, id DESC").Offset((page - 1) * perPage).Limit(perPage).Find(&posts).Error; err != nil {
+	if err := q.Order("published_at DESC, id DESC").Offset((page - 1) * perPage).Limit(perPage).Find(&posts).Error; err != nil {
 		wire.WriteOpaque500(w)
 		return
 	}
 	rows := make([]postJSON, 0, len(posts))
 	for _, post := range posts {
 		rows = append(rows, postJSON{
-			ID:        post.ID,
-			Title:     post.Title,
-			Slug:      post.Slug,
-			Body:      post.Body,
-			CreatedAt: wire.Time{Time: post.CreatedAt.UTC().Truncate(time.Second)},
+			ID:          post.ID,
+			Title:       post.Title,
+			Slug:        post.Slug,
+			Body:        post.Body,
+			PublishedAt: wire.Time{Time: post.PublishedAt.UTC().Truncate(time.Second)},
 		})
 	}
 	wire.WriteJSON(w, http.StatusOK, lagoon.Paginate(rows, page, perPage, total))