feat(advertising): implement advertising service with CRUD operations and validation

- Added advertising.go for managing advertising entries with Create and List functionalities.
- Implemented CreateAdvertisingParams with validation for name, email, and status.
- Created migrations for advertising table structure.
- Added tests for advertising parameters validation.

feat(promo): introduce promo management with validation and CRUD operations

- Added promo.go for managing promotional entries with Create, Update, and List functionalities.
- Implemented CreatePromoParams and UpdatePromoParams with validation for position, section, and weeks.
- Created migrations for promo table structure.
- Added tests for promo parameters validation.

feat(images): add image management service with upload and retrieval

- Added images.go for managing image uploads and retrieval from storage.
- Implemented SaveImageParams with validation for image description and data.
- Created migrations for images table structure.
- Added tests for image parameters validation and data parsing.

images/images_test.go

@@ -0,0 +1,94 @@
+package images
+
+import (
+	"encoding/base64"
+	"testing"
+
+	"encore.dev/types/uuid"
+)
+
+func TestSaveImageParams_Validate(t *testing.T) {
+	// Missing description
+	p := &SaveImageParams{
+		Description: "",
+		Data:        "abc",
+	}
+	if err := p.Validate(); err == nil {
+		t.Error("expected error for empty description, got nil")
+	}
+
+	// Missing data for new image (uuid is empty)
+	p = &SaveImageParams{
+		UUID:        "",
+		Description: "A test image",
+		Data:        "",
+	}
+	if err := p.Validate(); err == nil {
+		t.Error("expected error for empty data on new image, got nil")
+	}
+
+	// Valid new image (uuid is empty string)
+	p = &SaveImageParams{
+		UUID:        "",
+		Description: "A test image",
+		Data:        "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg==",
+	}
+	if err := p.Validate(); err != nil {
+		t.Errorf("expected valid params, got err: %v", err)
+	}
+
+	// Valid update (uuid present, empty data is allowed)
+	id, _ := uuid.NewV4()
+	p = &SaveImageParams{
+		UUID:        id.String(),
+		Description: "Updated description",
+	}
+	if err := p.Validate(); err != nil {
+		t.Errorf("expected valid update params, got err: %v", err)
+	}
+}
+
+func TestParseImageData(t *testing.T) {
+	raw := []byte("hello world")
+	encoded := base64.StdEncoding.EncodeToString(raw)
+
+	// Plain base64
+	data, ct, err := parseImageData(encoded, "image/jpeg")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if string(data) != "hello world" {
+		t.Errorf("expected 'hello world', got %q", string(data))
+	}
+	if ct != "image/jpeg" {
+		t.Errorf("expected 'image/jpeg', got %q", ct)
+	}
+
+	// Data URI
+	dataURI := "data:image/webp;base64," + encoded
+	data, ct, err = parseImageData(dataURI, "image/png")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if string(data) != "hello world" {
+		t.Errorf("expected 'hello world', got %q", string(data))
+	}
+	if ct != "image/webp" {
+		t.Errorf("expected 'image/webp', got %q", ct)
+	}
+}
+
+func TestImageCategoryConstants(t *testing.T) {
+	if ImageCategoryGeneral != "general" {
+		t.Errorf("expected general, got %s", ImageCategoryGeneral)
+	}
+	if ImageCategoryAvatar != "avatar" {
+		t.Errorf("expected avatar, got %s", ImageCategoryAvatar)
+	}
+	if ImageCategoryPromo != "promo" {
+		t.Errorf("expected promo, got %s", ImageCategoryPromo)
+	}
+	if ImageCategoryBanner != "banner" {
+		t.Errorf("expected banner, got %s", ImageCategoryBanner)
+	}
+}