feat: Add core services for user, category, item, and restaurant management, including caching and ownership verification.

src/cache/cache.keys.ts

@@ -1,7 +1,12 @@
 export const keys = {
   restaurantBySlug: (slug: string) => `restaurant:slug:${slug}`,
-  restaurantCategories: (restaurantId: string) => `restaurant:${restaurantId}:categories`,
+  restaurantById: (id: string) => `restaurant:id:${id}`,
+  restaurantCategories: (restaurantId: string) =>
+    `restaurant:${restaurantId}:categories`,
   restaurantItems: (restaurantId: string) => `restaurant:${restaurantId}:items`,
+  userRestaurants: (ownerId: string) => `user:${ownerId}:restaurants`,
   category: (categoryId: string) => `category:${categoryId}`,
+  categoryItems: (categoryId: string) => `category:${categoryId}:items`,
   item: (itemId: string) => `item:${itemId}`,
+  user: (userId: string) => `user:${userId}`,
 };