feat: manage fruits — full CRUD with images and synonyms (story #02)

Backend: domain structs, FruitRepository interface + pg implementation,
9 Echo v4 handlers (list/get/create/update/delete, image sub-resources),
migration 000002 (fruit_type ENUM, fruits, fruit_synonyms, fruit_images),
route-scoped BodyLimit("5M") for uploads, http.DetectContentType for serving.

Frontend: typed fetch API layer, Pinia setup-style fruitStore, FruitList
(paginated), FruitCreate, and FruitDetail (edit + synonyms editor + image
gallery). 25 backend unit tests + integration test; 18 frontend tests.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/internal/repository/fruit_repo_integration_test.go

@@ -0,0 +1,146 @@
+package repository_test
+
+import (
+	"context"
+	"os"
+	"testing"
+
+	"osdb/internal/database"
+	"osdb/internal/domain"
+	"osdb/internal/handler"
+	"osdb/internal/repository"
+)
+
+// pngFixture is a minimal valid PNG for byte round-trip testing.
+var pngFixture = []byte{
+	0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a,
+	0x00, 0x00, 0x00, 0x0d, 0x49, 0x48, 0x44, 0x52,
+	0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01,
+	0x08, 0x02, 0x00, 0x00, 0x00, 0x90, 0x77, 0x53,
+	0xde, 0x00, 0x00, 0x00, 0x0c, 0x49, 0x44, 0x41,
+	0x54, 0x08, 0xd7, 0x63, 0xf8, 0xcf, 0xc0, 0x00,
+	0x00, 0x00, 0x02, 0x00, 0x01, 0xe2, 0x21, 0xbc,
+	0x33, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4e,
+	0x44, 0xae, 0x42, 0x60, 0x82,
+}
+
+func TestFruitRepoIntegration(t *testing.T) {
+	dsn := os.Getenv("DATABASE_URL")
+	if dsn == "" {
+		t.Skip("DATABASE_URL not set — skipping integration test")
+	}
+
+	ctx := context.Background()
+	pool, err := database.Connect(ctx, dsn)
+	if err != nil {
+		t.Fatalf("connect: %v", err)
+	}
+	defer pool.Close()
+
+	repo := repository.NewFruitRepo(pool)
+
+	// cleanup after test
+	t.Cleanup(func() {
+		pool.Exec(ctx, `DELETE FROM fruits WHERE osdb_number LIKE 'TEST-%'`)
+	})
+
+	// Create
+	dto := domain.FruitWriteDTO{
+		Name:       "Boskop",
+		OSDBNumber: "TEST-001",
+		FruitType:  "Apfelsorten",
+		Synonyms:   []string{"Boskop-Renette", "Schöner aus Boskoop"},
+	}
+	f, err := repo.Create(ctx, dto)
+	if err != nil {
+		t.Fatalf("Create: %v", err)
+	}
+	if f.ID == 0 {
+		t.Fatal("want non-zero ID")
+	}
+	if len(f.Synonyms) != 2 {
+		t.Fatalf("want 2 synonyms got %d", len(f.Synonyms))
+	}
+
+	// Duplicate osdb_number → ErrDuplicateOSDBNumber
+	_, err = repo.Create(ctx, dto)
+	if err != handler.ErrDuplicateOSDBNumber {
+		t.Fatalf("want ErrDuplicateOSDBNumber got %v", err)
+	}
+
+	// Get (synonyms present)
+	got, err := repo.Get(ctx, f.ID)
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	if len(got.Synonyms) != 2 {
+		t.Fatalf("want 2 synonyms got %d", len(got.Synonyms))
+	}
+
+	// Update (replaces synonyms wholesale)
+	updated, err := repo.Update(ctx, f.ID, domain.FruitWriteDTO{
+		Name:       "Boskop Updated",
+		OSDBNumber: "TEST-001",
+		FruitType:  "Apfelsorten",
+		Synonyms:   []string{"Renamed"},
+	})
+	if err != nil {
+		t.Fatalf("Update: %v", err)
+	}
+	if updated.Name != "Boskop Updated" {
+		t.Fatalf("want updated name got %s", updated.Name)
+	}
+	if len(updated.Synonyms) != 1 || updated.Synonyms[0] != "Renamed" {
+		t.Fatalf("want [Renamed] got %v", updated.Synonyms)
+	}
+
+	// List
+	fruits, total, err := repo.List(ctx, 50, 0)
+	if err != nil {
+		t.Fatalf("List: %v", err)
+	}
+	if total < 1 {
+		t.Fatalf("want total >= 1 got %d", total)
+	}
+	_ = fruits
+
+	// AddImage + GetImageData byte round-trip
+	filename := "test.png"
+	imageType := "fruit"
+	img, err := repo.AddImage(ctx, f.ID, &filename, pngFixture, imageType, nil)
+	if err != nil {
+		t.Fatalf("AddImage: %v", err)
+	}
+	if img.ID == 0 {
+		t.Fatal("want non-zero image ID")
+	}
+
+	data, err := repo.GetImageData(ctx, f.ID, img.ID)
+	if err != nil {
+		t.Fatalf("GetImageData: %v", err)
+	}
+	if len(data) != len(pngFixture) {
+		t.Fatalf("byte round-trip: want %d bytes got %d", len(pngFixture), len(data))
+	}
+
+	// DeleteImage
+	if err := repo.DeleteImage(ctx, f.ID, img.ID); err != nil {
+		t.Fatalf("DeleteImage: %v", err)
+	}
+	if _, err := repo.GetImageData(ctx, f.ID, img.ID); err != handler.ErrNotFound {
+		t.Fatalf("after delete: want ErrNotFound got %v", err)
+	}
+
+	// Delete (cascade check)
+	if err := repo.Delete(ctx, f.ID); err != nil {
+		t.Fatalf("Delete: %v", err)
+	}
+	if _, err := repo.Get(ctx, f.ID); err != handler.ErrNotFound {
+		t.Fatalf("after delete: want ErrNotFound got %v", err)
+	}
+
+	// Update non-existent → ErrNotFound
+	if _, err := repo.Update(ctx, 999999, dto); err != handler.ErrNotFound {
+		t.Fatalf("Update non-existent: want ErrNotFound got %v", err)
+	}
+}