feat: добавил личные уведомления для пользователей

Реализовал хранение, получение и отметку прочитанными пользовательских уведомлений. Обновил фронтенд для отображения и управления уведомлениями в профиле студента.

backend/UniVerse.Infrastructure/Notifications/NotificationService.cs

@@ -1,20 +1,27 @@
 using Microsoft.Extensions.Logging;
+using Microsoft.EntityFrameworkCore;
+using UniVerse.Application.DTOs.Common;
 using UniVerse.Application.DTOs.Notifications;
 using UniVerse.Application.Interfaces;
+using UniVerse.Domain.Entities;
+using UniVerse.Infrastructure.Data;
 
 namespace UniVerse.Infrastructure.Notifications;
 
 public class NotificationService : INotificationService
 {
+    private readonly AppDbContext _db;
     private readonly IEnumerable<INotificationProvider> _providers;
     private readonly INotificationScheduler _scheduler;
     private readonly ILogger<NotificationService> _logger;
 
     public NotificationService(
+        AppDbContext db,
         IEnumerable<INotificationProvider> providers,
         INotificationScheduler scheduler,
         ILogger<NotificationService> logger)
     {
+        _db = db;
         _providers = providers;
         _scheduler = scheduler;
         _logger = logger;
@@ -46,4 +53,68 @@ public class NotificationService : INotificationService
 
         return _scheduler.ScheduleAsync(message, request.SendAt, cancellationToken);
     }
+
+    public async Task<UserNotificationDto> CreateUserNotificationAsync(
+        int userId,
+        string type,
+        string title,
+        string body,
+        CancellationToken cancellationToken = default)
+    {
+        ArgumentException.ThrowIfNullOrWhiteSpace(type);
+        ArgumentException.ThrowIfNullOrWhiteSpace(title);
+        ArgumentException.ThrowIfNullOrWhiteSpace(body);
+
+        var notification = new UserNotification
+        {
+            UserId = userId,
+            Type = type,
+            Title = title,
+            Body = body
+        };
+
+        _db.UserNotifications.Add(notification);
+        await _db.SaveChangesAsync(cancellationToken);
+
+        return ToDto(notification);
+    }
+
+    public async Task<PagedResult<UserNotificationDto>> GetUserNotificationsAsync(
+        int userId,
+        PaginationRequest pagination,
+        CancellationToken cancellationToken = default)
+    {
+        var query = _db.UserNotifications.Where(n => n.UserId == userId);
+        var total = await query.CountAsync(cancellationToken);
+        var items = await query
+            .OrderByDescending(n => n.CreatedAt)
+            .Skip((pagination.Page - 1) * pagination.PageSize)
+            .Take(pagination.PageSize)
+            .Select(n => new UserNotificationDto(
+                n.Id,
+                n.Type,
+                n.Title,
+                n.Body,
+                n.IsRead,
+                n.CreatedAt))
+            .ToListAsync(cancellationToken);
+
+        return PagedResult<UserNotificationDto>.Create(items, total, pagination.Page, pagination.PageSize);
+    }
+
+    public async Task MarkAllReadAsync(int userId, CancellationToken cancellationToken = default)
+    {
+        await _db.UserNotifications
+            .Where(n => n.UserId == userId && !n.IsRead)
+            .ExecuteUpdateAsync(setters => setters.SetProperty(n => n.IsRead, true), cancellationToken);
+    }
+
+    private static UserNotificationDto ToDto(UserNotification notification) => new(
+        notification.Id,
+        notification.Type,
+        notification.Title,
+        notification.Body,
+        notification.IsRead,
+        notification.CreatedAt
+    );
 }