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/GetMedia/GetMediaAssetQueryHandler.cs

@@ -0,0 +1,23 @@
+using LiteCqrs;
+using Microsoft.EntityFrameworkCore;
+using TeleWave.Application.Common.Interfaces;
+using TeleWave.Application.Common.Models;
+
+namespace TeleWave.Application.Media.GetMedia;
+
+public sealed class GetMediaAssetQueryHandler(IAppDbContext dbContext)
+    : IQueryHandler<GetMediaAssetQuery, Result<MediaAssetDto>>
+{
+    public async Task<Result<MediaAssetDto>> Handle(
+        GetMediaAssetQuery query,
+        CancellationToken cancellationToken
+    )
+    {
+        var asset = await dbContext.MediaAssets.AsNoTracking()
+            .FirstOrDefaultAsync(x => x.Id == query.Id, cancellationToken);
+
+        return asset is null
+            ? Result.Failure<MediaAssetDto>(MediaErrors.NotFound)
+            : Result.Success(MediaAssetDto.From(asset));
+    }
+}