build: add TypeScript configuration and generate declaration files

- Add tsconfig.json for TypeScript compilation with declaration and source map generation
- Generate .d.ts declaration files for all modules, services, controllers, and models
- Update package.json with NestJS dependencies and TypeScript development tools
- Include database files in the distribution output for persistence

dist/users/users.service.d.ts

@@ -0,0 +1,8 @@
+import { User } from '../models/user.model';
+export declare class UsersService {
+    private userModel;
+    constructor(userModel: typeof User);
+    findOne(username: string): Promise<User | null>;
+    findById(id: number): Promise<User | null>;
+    create(createUserDto: any): Promise<User>;
+}