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/recipes/recipe-matching.service.d.ts

@@ -0,0 +1,17 @@
+export type ProductMatchCandidate = {
+    id: number;
+    name: string;
+    canonicalName: string | null;
+    normalizedName: string;
+};
+export type IngredientSuggestion = {
+    productId: number;
+    productName: string;
+    score: number;
+};
+export declare class RecipeMatchingService {
+    private normalize;
+    private levenshtein;
+    private scoreProducts;
+    buildIngredientSuggestions(rawName: string, alternatives: string[] | undefined, products: ProductMatchCandidate[]): IngredientSuggestion[];
+}