feat: implement course listing and retrieval API with dedicated controller, service, and types.

Backend/src/controllers/CoursesController.ts

@@ -0,0 +1,25 @@
+import { Get, Body, Post, Route, Tags, SuccessResponse, Response, Delete, Controller, Security, Request, Put, Path } from 'tsoa';
+import { ValidationError } from '../middleware/errorHandler';
+import { createCourse, createCourseResponse, listCourseResponse } from '../types/courses.types';
+import { CoursesService } from '../services/courses.service';
+import { get } from 'http';
+
+@Route('api/courses')
+@Tags('Courses')
+export class CoursesController extends Controller {
+    private coursesService = new CoursesService();
+
+    @Get()
+    @SuccessResponse('200', 'Courses fetched successfully')
+    @Response('401', 'Invalid or expired token')
+    public async listCourses(): Promise<listCourseResponse> {
+        return await this.coursesService.ListCourses();
+    }
+
+    @Get('{id}')
+    @SuccessResponse('200', 'Course fetched successfully')
+    @Response('401', 'Invalid or expired token')
+    public async getCourseById(@Path() id: number): Promise<listCourseResponse> {
+        return await this.coursesService.ListCourses();
+    }
+}