Fix (?) issues related with concurrency

Core/EF/AutoSaveDbContext.Add.cs

@@ -0,0 +1,22 @@
+using Microsoft.EntityFrameworkCore.ChangeTracking;
+
+namespace Kruzya.TelegramBot.Core.EF;
+
+public abstract partial class AutoSaveDbContext
+{
+    public override EntityEntry Add(object entity)
+    {
+        var entry = base.Add(entity);
+        SaveChanges();
+
+        return entry;
+    }
+
+    public override EntityEntry<TEntity> Add<TEntity>(TEntity entity)
+    {
+        var entry = base.Add(entity);
+        SaveChanges();
+
+        return entry;
+    }
+}

Core/EF/AutoSaveDbContext.Remove.cs

@@ -0,0 +1,22 @@
+using Microsoft.EntityFrameworkCore.ChangeTracking;
+
+namespace Kruzya.TelegramBot.Core.EF;
+
+public abstract partial class AutoSaveDbContext
+{
+    public override EntityEntry Remove(object entity)
+    {
+        var entry = base.Remove(entity);
+        SaveChanges();
+
+        return entry;
+    }
+
+    public override EntityEntry<TEntity> Remove<TEntity>(TEntity entity)
+    {
+        var entry = base.Remove(entity);
+        SaveChanges();
+
+        return entry;
+    }
+}

Core/EF/AutoSaveDbContext.Update.cs

@@ -0,0 +1,22 @@
+using Microsoft.EntityFrameworkCore.ChangeTracking;
+
+namespace Kruzya.TelegramBot.Core.EF;
+
+public abstract partial class AutoSaveDbContext
+{
+    public override EntityEntry Update(object entity)
+    {
+        var entry = base.Update(entity);
+        SaveChanges();
+
+        return entry;
+    }
+
+    public override EntityEntry<TEntity> Update<TEntity>(TEntity entity)
+    {
+        var entry = base.Update(entity);
+        SaveChanges();
+
+        return entry;
+    }
+}

Core/EF/AutoSaveDbContext.cs

@@ -0,0 +1,12 @@
+using Microsoft.EntityFrameworkCore;
+
+namespace Kruzya.TelegramBot.Core.EF;
+
+/// <summary>
+/// EF database context with autosaving feature.
+/// </summary>
+public abstract partial class AutoSaveDbContext : DbContext
+{
+    protected AutoSaveDbContext(DbContextOptions options) : base(options)
+    {}
+}