feat: implement avatar upload functionality with presigned URL support for user profiles and announcement attachments.

Backend/src/controllers/UserController.ts

@@ -1,4 +1,4 @@
-import { Get, Body, Post, Route, Tags, SuccessResponse, Response, Example, Controller, Security, Request, Put } from 'tsoa';
+import { Get, Body, Post, Route, Tags, SuccessResponse, Response, Example, Controller, Security, Request, Put, UploadedFile } from 'tsoa';
 import { ValidationError } from '../middleware/errorHandler';
 import { UserService } from '../services/user.service';
 import {
@@ -7,7 +7,8 @@ import {
     ProfileUpdate,
     ProfileUpdateResponse,
     ChangePasswordRequest,
-    ChangePasswordResponse
+    ChangePasswordResponse,
+    updateAvatarResponse
 } from '../types/user.types';
 import { ChangePassword } from '../types/auth.types';
 import { profileUpdateSchema, changePasswordSchema } from "../validators/user.validator";
@@ -78,4 +79,31 @@ export class UserController {
 
         return await this.userService.changePassword(token, body.oldPassword, body.newPassword);
     }
+
+    /**
+     * Upload user avatar picture
+     * @param request Express request object with JWT token in Authorization header
+     * @param file Avatar image file
+     */
+    @Post('upload-avatar')
+    @Security('jwt')
+    @SuccessResponse('200', 'Avatar uploaded successfully')
+    @Response('401', 'Invalid or expired token')
+    @Response('400', 'Validation error')
+    public async uploadAvatar(
+        @Request() request: any,
+        @UploadedFile() file: Express.Multer.File
+    ): Promise<updateAvatarResponse> {
+        const token = request.headers.authorization?.replace('Bearer ', '');
+        if (!token) throw new ValidationError('No token provided');
+
+        // Validate file type (images only)
+        if (!file.mimetype?.startsWith('image/')) throw new ValidationError('Only image files are allowed');
+
+        // Validate file size (max 5MB)
+        const maxSize = 5 * 1024 * 1024; // 5MB
+        if (file.size > maxSize) throw new ValidationError('File size must be less than 5MB');
+
+        return await this.userService.uploadAvatarPicture(token, file);
+    }
 }