feat: add categories and favorites schemas with integrations

Added `categories` and `favorites` database schemas with full type inference support. Integrated categories into `content` schema with new properties (`categoryId`, `slug`, `views`, and `usageCount`). Updated `tags` schema to include `userId` with reference to `users`. Exported new schemas in index for broader usage.

backend/src/database/schemas/content.ts

@@ -8,6 +8,7 @@ import {
 	uuid,
 	varchar,
 } from "drizzle-orm/pg-core";
+import { categories } from "./categories";
 import { tags } from "./tags";
 import { users } from "./users";
 
@@ -21,10 +22,16 @@ export const contents = pgTable(
 			.notNull()
 			.references(() => users.uuid, { onDelete: "cascade" }),
 		type: contentType("type").notNull(),
+		categoryId: uuid("category_id").references(() => categories.id, {
+			onDelete: "set null",
+		}),
 		title: varchar("title", { length: 255 }).notNull(),
+		slug: varchar("slug", { length: 255 }).notNull().unique(),
 		storageKey: varchar("storage_key", { length: 512 }).notNull().unique(), // Clé interne S3
 		mimeType: varchar("mime_type", { length: 128 }).notNull(), // Pour le Content-Type HTTP
 		fileSize: integer("file_size").notNull(), // Taille en octets
+		views: integer("views").notNull().default(0),
+		usageCount: integer("usage_count").notNull().default(0),
 		createdAt: timestamp("created_at", { withTimezone: true })
 			.notNull()
 			.defaultNow(),