feat: add rematch functionality for recipe ingredients and enhance inventory management

- Added a new API path for rematching recipe ingredients in `api_paths.dart`.
- Implemented a manual product creation dialog in `inventory_screen.dart` to allow users to create new products directly.
- Integrated the rematch functionality in `recipe_repository.dart` to handle rematching of recipe ingredients.
- Updated the recipe detail screen to include a button for triggering the rematch process.
- Introduced a new `RecipeMatchingService` in the backend to handle ingredient matching logic.
- Added database migration to include `aiEngineEnabled` column in the User table.

Co-authored-by: Copilot <copilot@github.com>

backend/dist/receipt-import/receipt-import.service.js

@@ -141,7 +141,7 @@ let ReceiptImportService = ReceiptImportService_1 = class ReceiptImportService {
     async parseReceipt(file, _isPremium = false, userId) {
         const rawItems = await this.parseReceiptViaImporter(file);
         const matched = await this.matchProducts(rawItems, userId);
-        return this.enrichWithAiCategories(matched);
+        return this.enrichWithAiCategories(matched, userId);
     }
     async parseReceiptViaImporter(file) {
         const form = new FormData();
@@ -283,7 +283,7 @@ let ReceiptImportService = ReceiptImportService_1 = class ReceiptImportService {
         }
         return best?.product;
     }
-    async enrichWithAiCategories(items) {
+    async enrichWithAiCategories(items, userId) {
         let categories;
         try {
             categories = await this.categoriesService.findFlattened();
@@ -291,6 +291,12 @@ let ReceiptImportService = ReceiptImportService_1 = class ReceiptImportService {
         catch {
             return items;
         }
+        const user = userId
+            ? await this.prisma.user.findUnique({
+                where: { id: userId },
+                select: { aiEngineEnabled: true },
+            })
+            : null;
         const enriched = [];
         for (const item of items) {
             if (!item.rawName) {
@@ -347,9 +353,14 @@ let ReceiptImportService = ReceiptImportService_1 = class ReceiptImportService {
                     pushTrace(`rule fallback applied -> "${byRule.path}"`);
                 }
                 if (!nextSuggestion) {
-                    pushTrace('ai invoked');
-                    nextSuggestion = await this.aiService.suggestCategory(item.rawName, categories);
-                    pushTrace(`ai result -> "${nextSuggestion.path}" (${nextSuggestion.confidence})`);
+                    if (user?.aiEngineEnabled) {
+                        pushTrace('ai invoked');
+                        nextSuggestion = await this.aiService.suggestCategory(item.rawName, categories);
+                        pushTrace(`ai result -> "${nextSuggestion.path}" (${nextSuggestion.confidence})`);
+                    }
+                    else {
+                        pushTrace('ai skipped, feature disabled');
+                    }
                 }
                 else {
                     pushTrace(`ai skipped, current -> "${nextSuggestion.path}"`);