feat: implement receipt alias functionality with CRUD operations and integrate with receipt import

backend/prisma/migrations/20260416200000_add_receipt_alias/migration.sql

@@ -0,0 +1,14 @@
+-- CreateTable
+CREATE TABLE `ReceiptAlias` (
+    `id` INTEGER NOT NULL AUTO_INCREMENT,
+    `receiptName` VARCHAR(191) NOT NULL,
+    `productId` INTEGER NOT NULL,
+    `createdAt` DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
+
+    UNIQUE INDEX `ReceiptAlias_receiptName_key`(`receiptName`),
+    INDEX `ReceiptAlias_productId_idx`(`productId`),
+    PRIMARY KEY (`id`)
+) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
+
+-- AddForeignKey
+ALTER TABLE `ReceiptAlias` ADD CONSTRAINT `ReceiptAlias_productId_fkey` FOREIGN KEY (`productId`) REFERENCES `Product`(`id`) ON DELETE CASCADE ON UPDATE CASCADE;

backend/prisma/schema.prisma

@@ -21,6 +21,7 @@ model Product {
   inventoryItems    InventoryItem[]
   recipeIngredients RecipeIngredient[]
   pantryItems       PantryItem[]
+  receiptAliases    ReceiptAlias[]
 }
 
 model InventoryItem {
@@ -95,6 +96,14 @@ model PantryItem {
   updatedAt DateTime @updatedAt
 }
 
+model ReceiptAlias {
+  id           Int      @id @default(autoincrement())
+  receiptName  String   @unique  // normaliserat kvittonamn (lowercase, trim)
+  productId    Int
+  product      Product  @relation(fields: [productId], references: [id], onDelete: Cascade)
+  createdAt    DateTime @default(now())
+}
+
 model MealPlanEntry {
   id        Int      @id @default(autoincrement())
   date      DateTime @db.Date