feat(auth): implement role seeding on application bootstrap

- Added `onApplicationBootstrap` to seed default roles if none exist.
- Introduced `seedRoles` method to handle role creation with logging.
- Updated `RbacRepository` with `countRoles` and `createRole` methods.
- Added unit tests to ensure role seeding logic functions correctly.

backend/src/auth/repositories/rbac.repository.ts

@@ -39,4 +39,22 @@ export class RbacRepository {
 
 		return Array.from(new Set(result.map((p) => p.slug)));
 	}
+
+	async countRoles(): Promise<number> {
+		const result = await this.databaseService.db
+			.select({ count: roles.id })
+			.from(roles);
+		return result.length;
+	}
+
+	async createRole(name: string, slug: string, description?: string) {
+		return this.databaseService.db
+			.insert(roles)
+			.values({
+				name,
+				slug,
+				description,
+			})
+			.returning();
+	}
 }