Implement media storage and processing features: update configuration in .env.example and appsettings files, enhance Docker setup for media storage, and add media-related services and database entities. Include ffmpeg for media handling and adjust Kestrel settings for large file uploads.

backend/src/TeleWave.Application/Media/Delete/DeleteMediaAssetCommandHandler.cs

@@ -0,0 +1,29 @@
+using LiteCqrs;
+using Microsoft.EntityFrameworkCore;
+using TeleWave.Application.Common.Interfaces;
+using TeleWave.Application.Common.Models;
+
+namespace TeleWave.Application.Media.Delete;
+
+public sealed class DeleteMediaAssetCommandHandler(IAppDbContext dbContext, IMediaStorage storage)
+    : ICommandHandler<DeleteMediaAssetCommand, Result>
+{
+    public async Task<Result> Handle(
+        DeleteMediaAssetCommand command,
+        CancellationToken cancellationToken
+    )
+    {
+        var asset = await dbContext.MediaAssets.FirstOrDefaultAsync(
+            x => x.Id == command.Id,
+            cancellationToken
+        );
+        if (asset is null)
+            return Result.Failure(MediaErrors.NotFound);
+
+        // TODO(этап 2): запретить удаление, пока ассет используется в расписании/пуле канала.
+        storage.DeleteAssetArtifacts(asset.Id, asset.OriginalExtension);
+        dbContext.MediaAssets.Remove(asset);
+
+        return Result.Success();
+    }
+}