Refactor EF migration logic and minor code cleanups

- Moved EF Core migration logic to new DbContextExtensions.ApplyMigrations<TContext> with optional logging; HostExtensions now delegates to it.
- Made DeletedAtUtc property in IDeletableEntity interface-level only.
- Removed unnecessary casts in AesGcmStreamCipher and AesGcmStreamFormat.
- Fixed extern/static order in ShellLink ExtractIconEx declaration.
- Made fields private and explicit in StopwatchDebuggerTests.

Author: Vadim Belov

Sources/EasyExtensions.Crypto/AesGcmStreamCipher.cs

@@ -107,7 +107,7 @@ public AesGcmStreamCipher(ReadOnlyMemory<byte> masterKey, int keyId = 1, int? th
             {
                 throw new ArgumentOutOfRangeException(nameof(windowCap), "Window cap must be >= 4.");
             }
-            if (memoryLimitBytes.HasValue && memoryLimitBytes.Value < (long)(MinChunkSize * 4))
+            if (memoryLimitBytes.HasValue && memoryLimitBytes.Value < MinChunkSize * 4)
             {
                 throw new ArgumentOutOfRangeException(nameof(memoryLimitBytes), "Memory limit too small for safe operation.");
             }

Sources/EasyExtensions.Crypto/Internals/AesGcmStreamFormat.cs

@@ -104,7 +104,7 @@ public static void BuildChunkHeader(Span<byte> header, int keyId, Tag128 tag, in
             offset += MagicBytes.Length;
             BinaryPrimitives.WriteInt32LittleEndian(header[offset..], required);
             offset += sizeof(int);
-            BinaryPrimitives.WriteInt64LittleEndian(header[offset..], (long)textLength);
+            BinaryPrimitives.WriteInt64LittleEndian(header[offset..], textLength);
             offset += sizeof(long);
             BinaryPrimitives.WriteInt32LittleEndian(header[offset..], keyId);
             offset += sizeof(int);

Sources/EasyExtensions.EntityFrameworkCore/Abstractions/IDeletableEntity.cs

@@ -11,7 +11,7 @@ public interface IDeletableEntity
         /// When entity was deleted.
         /// </summary>
         [Column("deleted_at_utc")]
-        public DateTime? DeletedAtUtc { get; set; }
+        DateTime? DeletedAtUtc { get; set; }
 
         /// <summary>
         /// Calling this method must sets <see cref="DeletedAtUtc"/> to <see cref="DateTime.UtcNow"/>.

Sources/EasyExtensions.EntityFrameworkCore/Extensions/DbContextExtensions.cs

@@ -0,0 +1,34 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+
+namespace EasyExtensions.EntityFrameworkCore.Extensions
+{
+    /// <summary>
+    /// Provides extension methods for applying database migrations to a DbContext instance.
+    /// </summary>
+    public static class DbContextExtensions
+    {
+        /// <summary>
+        /// Applies all pending database migrations for the specified DbContext instance.
+        /// </summary>
+        /// <remarks>This method checks for any pending migrations and applies them in order. If there are
+        /// no pending migrations, no action is taken. Logging is performed for each migration if a logger is
+        /// provided.</remarks>
+        /// <typeparam name="TContext">The type of the DbContext to apply migrations to.</typeparam>
+        /// <param name="context">The DbContext instance whose pending migrations will be applied. Cannot be null.</param>
+        /// <param name="logger">An optional logger used to record information about the migration process. If null, no logging is performed.</param>
+        public static void ApplyMigrations<TContext>(this TContext context, ILogger? logger) where TContext : DbContext
+        {
+            var migrations = context.Database.GetPendingMigrations();
+            if (migrations.Any())
+            {
+                foreach (var migration in migrations)
+                {
+                    logger?.LogInformation("Applying migration {Migration}.", migration);
+                }
+                context.Database.Migrate();
+                logger?.LogInformation("Migrations applied.");
+            }
+        }
+    }
+}

Sources/EasyExtensions.EntityFrameworkCore/Extensions/HostExtensions.cs

@@ -19,17 +19,8 @@ public static IHost ApplyMigrations<TContext>(this IHost host) where TContext :
             using (var serviceScope = host.Services.GetService<IServiceScopeFactory>()!.CreateScope())
             {
                 var context = serviceScope.ServiceProvider.GetRequiredService<TContext>();
-                var migrations = context.Database.GetPendingMigrations();
-                if (migrations.Any())
-                {
-                    var logger = serviceScope.ServiceProvider.GetRequiredService<ILogger<DbContext>>();
-                    foreach (var migration in migrations)
-                    {
-                        logger.LogInformation("Applying migration {Migration}.", migration);
-                    }
-                    context.Database.Migrate();
-                    logger.LogInformation("Migrations applied.");
-                }
+                var logger = serviceScope.ServiceProvider.GetRequiredService<ILogger<DbContext>>();
+                context.ApplyMigrations(logger);
             }
             return host;
         }

Sources/EasyExtensions.Tests/StopwatchDebuggerTests.cs

@@ -4,9 +4,9 @@ namespace EasyExtensions.Tests
 {
     internal class StopwatchDebuggerTests
     {
-        readonly StopwatchDebugger debugger;
-        string action = string.Empty;
-        TimeSpan elapsed = TimeSpan.Zero;
+        private readonly StopwatchDebugger debugger;
+        private string action = string.Empty;
+        private TimeSpan elapsed = TimeSpan.Zero;
 
         public StopwatchDebuggerTests()
         {

Sources/EasyExtensions.Windows/ShellLink.cs

@@ -397,7 +397,7 @@ private struct FILETIME
         private class UnmanagedMethods
         {
             [DllImport("Shell32", CharSet = CharSet.Auto)]
-            internal extern static int ExtractIconEx([MarshalAs(UnmanagedType.LPTStr)]
+            internal static extern int ExtractIconEx([MarshalAs(UnmanagedType.LPTStr)]
                 string lpszFile, int nIconIndex, IntPtr[]? phIconLarge, IntPtr[]? phIconSmall, int nIcons);
 
             [DllImport("user32")]