feat(auth): add PATCH /auth/profile endpoint for user profile updates

Implement user profile update with fullName, avatarUrl, and email fields.
Email changes include uniqueness validation and Email VO verification.
Follows existing DDD/CQRS patterns with cache invalidation.
19 unit tests covering handler logic and DTO validation.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/api/src/modules/auth/application/commands/update-profile/update-profile.command.ts

@@ -0,0 +1,8 @@
+export class UpdateProfileCommand {
+  constructor(
+    public readonly userId: string,
+    public readonly fullName?: string,
+    public readonly avatarUrl?: string,
+    public readonly email?: string,
+  ) {}
+}

apps/api/src/modules/auth/application/commands/update-profile/update-profile.handler.ts

@@ -0,0 +1,83 @@
+import { Inject, InternalServerErrorException } from '@nestjs/common';
+import { CommandHandler, ICommandHandler } from '@nestjs/cqrs';
+import {
+  CachePrefix,
+  CacheService,
+  ConflictException,
+  DomainException,
+  LoggerService,
+  NotFoundException,
+  ValidationException,
+} from '@modules/shared';
+import { Email } from '../../../domain/value-objects/email.vo';
+import { IUserRepository, USER_REPOSITORY } from '../../../domain/repositories/user.repository';
+import { UpdateProfileCommand } from './update-profile.command';
+
+export interface UpdateProfileResultDto {
+  id: string;
+  fullName: string;
+  avatarUrl: string | null;
+  email: string | null;
+  updatedAt: Date;
+}
+
+@CommandHandler(UpdateProfileCommand)
+export class UpdateProfileHandler implements ICommandHandler<UpdateProfileCommand> {
+  constructor(
+    @Inject(USER_REPOSITORY) private readonly userRepo: IUserRepository,
+    private readonly cache: CacheService,
+    private readonly logger: LoggerService,
+  ) {}
+
+  async execute(command: UpdateProfileCommand): Promise<UpdateProfileResultDto> {
+    try {
+      const user = await this.userRepo.findById(command.userId);
+      if (!user) {
+        throw new NotFoundException('Người dùng', command.userId);
+      }
+
+      // Validate and resolve email if provided
+      let newEmail: Email | null | undefined;
+      if (command.email !== undefined) {
+        const emailResult = Email.create(command.email);
+        if (emailResult.isErr) {
+          throw new ValidationException(emailResult.unwrapErr());
+        }
+        const email = emailResult.unwrap();
+
+        // Check if email is actually changing
+        if (user.email?.value !== email.value) {
+          // Check uniqueness
+          const existingUser = await this.userRepo.findByEmail(email.value);
+          if (existingUser && existingUser.id !== command.userId) {
+            throw new ConflictException('Email đã được sử dụng bởi tài khoản khác');
+          }
+          newEmail = email;
+        }
+      }
+
+      user.updateProfile(command.fullName, command.avatarUrl, newEmail);
+      await this.userRepo.update(user);
+
+      await this.cache.invalidate(
+        CacheService.buildKey(CachePrefix.USER_PROFILE, command.userId),
+      );
+
+      return {
+        id: user.id,
+        fullName: user.fullName,
+        avatarUrl: user.avatarUrl,
+        email: user.email?.value ?? null,
+        updatedAt: user.updatedAt,
+      };
+    } catch (error) {
+      if (error instanceof DomainException) throw error;
+      this.logger.error(
+        `Failed to update profile: ${error instanceof Error ? error.message : error}`,
+        error instanceof Error ? error.stack : undefined,
+        this.constructor.name,
+      );
+      throw new InternalServerErrorException('Không thể cập nhật hồ sơ người dùng');
+    }
+  }
+}