initial: Backend Auth Module + Design System + Complete Documentation

- Setup NestJS with TypeScript, ConfigModule, JWT authentication
- Implemented Auth Module with signup, login, logout endpoints
- Created DTOs with validation (SignupDto, LoginDto)
- JWT Strategy with Passport integration for token validation
- JwtAuthGuard for route protection with Bearer tokens
- CurrentUser decorator for dependency injection
- Supabase integration for user management and auth
- Complete API documentation (API.md) with all endpoints
- Design System for Web (Next.js + Tailwind) and Mobile (Flutter)
- Comprehensive project documentation and roadmap
- Environment configuration with Joi schema validation
- Ready for Tasks Module and RLS implementation

backend-api/test/app.e2e-spec.ts

@@ -0,0 +1,25 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { INestApplication } from '@nestjs/common';
+import request from 'supertest';
+import { App } from 'supertest/types';
+import { AppModule } from './../src/app.module';
+
+describe('AppController (e2e)', () => {
+  let app: INestApplication<App>;
+
+  beforeEach(async () => {
+    const moduleFixture: TestingModule = await Test.createTestingModule({
+      imports: [AppModule],
+    }).compile();
+
+    app = moduleFixture.createNestApplication();
+    await app.init();
+  });
+
+  it('/ (GET)', () => {
+    return request(app.getHttpServer())
+      .get('/')
+      .expect(200)
+      .expect('Hello World!');
+  });
+});