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/users/users.controller.d.ts

@@ -8,6 +8,9 @@ declare class SetPremiumDto {
 declare class SetRecipeSharingDto {
     canShareRecipes: boolean;
 }
+declare class SetAiEngineEnabledDto {
+    aiEngineEnabled: boolean;
+}
 declare class AdminCreateUserDto {
     username: string;
     email: string;
@@ -56,6 +59,7 @@ export declare class UsersController {
         role: string;
         isPremium: boolean;
         canShareRecipes: boolean;
+        aiEngineEnabled: boolean;
     }[]>;
     setRole(id: number, caller: {
         userId: number;
@@ -76,6 +80,11 @@ export declare class UsersController {
         username: string;
         canShareRecipes: boolean;
     }>;
+    setAiEngineEnabled(id: number, dto: SetAiEngineEnabledDto): Promise<{
+        id: number;
+        username: string;
+        aiEngineEnabled: boolean;
+    }>;
     adminCreateUser(dto: AdminCreateUserDto): Promise<{
         id: number;
         username: string;