fix: migrate to IDbContextFactory and remove direct AppDbContext from DI (#11)

Reviewed-on: #11
Co-authored-by: Marek Jasiński <jasins.marek@gmail.com>
Co-committed-by: Marek Jasiński <jasins.marek@gmail.com>

src/NexusReader.Infrastructure/Handlers/UpdateReadingProgressCommandHandler.cs

@@ -4,27 +4,28 @@ using Microsoft.AspNetCore.SignalR;
 using Microsoft.EntityFrameworkCore;
 using NexusReader.Application.Commands.Sync;
 using NexusReader.Domain.Entities;
-using NexusReader.Infrastructure.Persistence;
+using NexusReader.Data.Persistence;
 using NexusReader.Infrastructure.RealTime;
 
 namespace NexusReader.Infrastructure.Handlers;
 
 public class UpdateReadingProgressCommandHandler : IRequestHandler<UpdateReadingProgressCommand, Result>
 {
-    private readonly AppDbContext _context;
+    private readonly IDbContextFactory<AppDbContext> _dbContextFactory;
     private readonly IHubContext<SyncHub> _hubContext;
 
     public UpdateReadingProgressCommandHandler(
-        AppDbContext context, 
+        IDbContextFactory<AppDbContext> dbContextFactory, 
         IHubContext<SyncHub> hubContext)
     {
-        _context = context;
+        _dbContextFactory = dbContextFactory;
         _hubContext = hubContext;
     }
 
     public async Task<Result> Handle(UpdateReadingProgressCommand request, CancellationToken cancellationToken)
     {
-        var user = await _context.Users.FirstOrDefaultAsync(u => u.Id == request.UserId, cancellationToken);
+        using var context = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
+        var user = await context.Users.FirstOrDefaultAsync(u => u.Id == request.UserId, cancellationToken);
         if (user == null)
         {
             return Result.Fail("User not found.");
@@ -34,7 +35,7 @@ public class UpdateReadingProgressCommandHandler : IRequestHandler<UpdateReading
         user.LastReadPageId = request.PageId;
         user.LastReadAt = now;
 
-        await _context.SaveChangesAsync(cancellationToken);
+        await context.SaveChangesAsync(cancellationToken);
 
         // Broadcast to other devices
         await _hubContext.Clients