feat(api): list an author's published posts at /authors/{author}/posts

- AuthorPosts reuses the /posts published predicate, per_page clamp, sort allow-list and row serializer
- Bearer tokens are ignored; drafts and scheduled posts never appear
- Both author routes share one resolve-or-respond helper for identical 404/500 paths
- Document query keys, envelope and 404 in README

controllers/api/authors.go

@@ -8,6 +8,7 @@ import (
 
 	"git.golem15.com/golem15/sm-journal-plugin/models"
 	"git.golem15.com/golem15/summercms/modules/backpack"
+	"git.golem15.com/golem15/summercms/modules/lagoon"
 	"git.golem15.com/golem15/summercms/modules/wire"
 	"gorm.io/gorm"
 )
@@ -129,3 +130,37 @@ func AuthorShow(app *backpack.App) http.HandlerFunc {
 		wire.WriteJSON(w, http.StatusOK, map[string]any{"data": authorProfile(row)})
 	}
 }
+
+// AuthorPosts is GET /_journal/api/v1/authors/{author}/posts: that author's
+// published posts, paginated like GET /posts. Bearer tokens are ignored.
+func AuthorPosts(app *backpack.App) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		db, author, ok := authorOrRespond(app, w, r)
+		if !ok {
+			return
+		}
+		perPage := clampPerPage(r.URL.Query().Get("per_page"))
+		page := max(1, atoiDefault(r.URL.Query().Get("page"), 1))
+
+		q := applyPublished(db.Model(&models.Post{}).
+			Preload("User").Preload("Categories").Preload("Tags")).
+			Where("user_id = ?", author.ID)
+
+		var total int64
+		if err := q.Count(&total).Error; err != nil {
+			writeAPIError(w, http.StatusInternalServerError, "Internal server error")
+			return
+		}
+		order := listOrder(strings.TrimSpace(r.URL.Query().Get("sort")), false)
+		var posts []models.Post
+		if err := q.Order(order).Offset((page - 1) * perPage).Limit(perPage).Find(&posts).Error; err != nil {
+			writeAPIError(w, http.StatusInternalServerError, "Internal server error")
+			return
+		}
+		rows := make([]map[string]any, 0, len(posts))
+		for i := range posts {
+			rows = append(rows, serializePost(&posts[i], db))
+		}
+		wire.WriteJSON(w, http.StatusOK, lagoon.Paginate(rows, page, perPage, total))
+	}
+}