chore: move backend to hono + typescript (#558)

* feat: setup secure presigned uploads and downloads

* clean up

* update lock

* Get presigned url finally working

* 557: Migrate backend to hono + ts

* chore: update Dockerfile and package.json for backend configuration

* add dev command

* remove unused packages

* Enhance backend API and frontend components for course management

- Updated CORS configuration in the backend to allow specific methods and headers.
- Refactored lesson download endpoint to use a new route for PDF downloads.
- Removed unused certificate download functionality from the lesson router.
- Updated frontend components to reflect changes in API endpoints and improve video upload functionality.
- Introduced new video upload component and adjusted video handling in lesson materials.
- Cleaned up unnecessary imports and optimized component structure for better performance.

* PR cleanups

* Enhance email configuration by adding SMTP_SENDER environment variable

- Updated docker-compose.yaml to include SMTP_SENDER.
- Modified Dockerfile to accept SMTP_SENDER as an argument.
- Updated environment schema in env.ts to define SMTP_SENDER as optional.
- Adjusted mail service to use SMTP_SENDER for the email 'from' field.
- Updated documentation to reflect the new SMTP_SENDER variable.

* Remove debug log statement from sendEmail function

---------

Co-authored-by: Iniubong Obonguko <iniubongobonguko2018@gmail.com>

apps/backend/src/routes/course/lesson.ts

@@ -0,0 +1,35 @@
+import { Context, Hono } from 'hono';
+import { ZCertificateDownload, ZLessonDownloadContent } from '$src/types/course/lesson';
+
+import { generateLessonPdf } from '$src/utils/lesson';
+
+export const lessonRouter = new Hono();
+
+lessonRouter.post('/download/pdf', async (c: Context) => {
+  try {
+    const data = await c.req.json();
+    const validatedData = ZLessonDownloadContent.parse(data);
+
+    const pdfBuffer = await generateLessonPdf(validatedData);
+
+    c.header('Content-Type', 'application/pdf');
+    return c.body(
+      new ReadableStream({
+        start(controller) {
+          controller.enqueue(pdfBuffer);
+          controller.close();
+        }
+      })
+    );
+  } catch (error) {
+    console.error('Error generating lesson PDF:', error);
+    return c.json(
+      {
+        success: false,
+        error: error instanceof Error ? error.message : 'Unknown error occurred',
+        details: error
+      },
+      400
+    );
+  }
+});