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>

flutter/lib/features/recipes/presentation/recipe_detail_screen.dart

@@ -521,6 +521,29 @@ class _InventoryPreviewSectionState
     extends ConsumerState<_InventoryPreviewSection> {
   bool _loaded = false;
 
+  Future<void> _runRematch() async {
+    try {
+      final token = ref.read(authStateProvider).maybeWhen(
+        data: (t) => t,
+        orElse: () => null,
+            ) ??
+            await ref.read(authStateProvider.future);
+      await ref
+          .read(recipeRepositoryProvider)
+          .rematchRecipeIngredients(widget.recipeId, token: token);
+      ref.invalidate(recipeAnalysisProvider(widget.recipeId));
+      if (!mounted) return;
+      ScaffoldMessenger.of(context).showSnackBar(
+        const SnackBar(content: Text('Matchning uppdaterad')),
+      );
+    } catch (e) {
+      if (!mounted) return;
+      ScaffoldMessenger.of(context).showSnackBar(
+        buildCopyableErrorSnackBar(context, mapErrorToUserMessage(e, context)),
+      );
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
     final theme = Theme.of(context);
@@ -538,6 +561,12 @@ class _InventoryPreviewSectionState
                 icon: const Icon(Icons.search, size: 16),
                 label: const Text('Kontrollera inventarie'),
               ),
+            if (_loaded)
+              IconButton(
+                tooltip: 'Kör om matchning',
+                icon: const Icon(Icons.auto_fix_high),
+                onPressed: _runRematch,
+              ),
             if (_loaded)
               IconButton(
                 tooltip: 'Uppdatera',