feat: add modular services and repositories for improved code organization

Introduce repository pattern across multiple services, including `favorites`, `tags`, `sessions`, `reports`, `auth`, and more. Decouple crypto functionalities into modular services like `HashingService`, `JwtService`, and `EncryptionService`. Improve testability and maintainability by simplifying dependencies and consolidating utility logic.

backend/src/auth/rbac.service.spec.ts

@@ -1,15 +1,14 @@
 import { Test, TestingModule } from "@nestjs/testing";
-import { DatabaseService } from "../database/database.service";
 import { RbacService } from "./rbac.service";
+import { RbacRepository } from "./repositories/rbac.repository";
 
 describe("RbacService", () => {
 	let service: RbacService;
+	let repository: RbacRepository;
 
-	const mockDb = {
-		select: jest.fn().mockReturnThis(),
-		from: jest.fn().mockReturnThis(),
-		innerJoin: jest.fn().mockReturnThis(),
-		where: jest.fn(),
+	const mockRbacRepository = {
+		findRolesByUserId: jest.fn(),
+		findPermissionsByUserId: jest.fn(),
 	};
 
 	beforeEach(async () => {
@@ -18,15 +17,14 @@ describe("RbacService", () => {
 			providers: [
 				RbacService,
 				{
-					provide: DatabaseService,
-					useValue: {
-						db: mockDb,
-					},
+					provide: RbacRepository,
+					useValue: mockRbacRepository,
 				},
 			],
 		}).compile();
 
 		service = module.get<RbacService>(RbacService);
+		repository = module.get<RbacRepository>(RbacRepository);
 	});
 
 	it("should be defined", () => {
@@ -36,34 +34,26 @@ describe("RbacService", () => {
 	describe("getUserRoles", () => {
 		it("should return user roles", async () => {
 			const userId = "user-id";
-			const mockRoles = [{ slug: "admin" }, { slug: "user" }];
-			mockDb.where.mockResolvedValue(mockRoles);
+			const mockRoles = ["admin", "user"];
+			mockRbacRepository.findRolesByUserId.mockResolvedValue(mockRoles);
 
 			const result = await service.getUserRoles(userId);
 
-			expect(result).toEqual(["admin", "user"]);
-			expect(mockDb.select).toHaveBeenCalled();
-			expect(mockDb.from).toHaveBeenCalled();
-			expect(mockDb.innerJoin).toHaveBeenCalled();
+			expect(result).toEqual(mockRoles);
+			expect(repository.findRolesByUserId).toHaveBeenCalledWith(userId);
 		});
 	});
 
 	describe("getUserPermissions", () => {
-		it("should return unique user permissions", async () => {
+		it("should return user permissions", async () => {
 			const userId = "user-id";
-			const mockPermissions = [
-				{ slug: "read" },
-				{ slug: "write" },
-				{ slug: "read" }, // Duplicate
-			];
-			mockDb.where.mockResolvedValue(mockPermissions);
+			const mockPermissions = ["read", "write"];
+			mockRbacRepository.findPermissionsByUserId.mockResolvedValue(mockPermissions);
 
 			const result = await service.getUserPermissions(userId);
 
-			expect(result).toEqual(["read", "write"]);
-			expect(mockDb.select).toHaveBeenCalled();
-			expect(mockDb.from).toHaveBeenCalled();
-			expect(mockDb.innerJoin).toHaveBeenCalledTimes(2);
+			expect(result).toEqual(mockPermissions);
+			expect(repository.findPermissionsByUserId).toHaveBeenCalledWith(userId);
 		});
 	});
 });