✨ Drive resource recycler, delete files in batch

DysonNetwork.Drive/Startup/BroadcastEventHandler.cs

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+using System.Text.Json;
+using DysonNetwork.Drive.Storage;
+using DysonNetwork.Shared.Stream;
+using Microsoft.EntityFrameworkCore;
+using NATS.Client.Core;
+
+namespace DysonNetwork.Drive.Startup;
+
+public class BroadcastEventHandler(
+    INatsConnection nats,
+    ILogger<BroadcastEventHandler> logger,
+    FileService fs,
+    AppDatabase db
+) : BackgroundService
+{
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        await foreach (var msg in nats.SubscribeAsync<byte[]>("accounts.deleted", cancellationToken: stoppingToken))
+        {
+            try
+            {
+                var evt = JsonSerializer.Deserialize<AccountDeletedEvent>(msg.Data);
+                if (evt == null) continue;
+
+                logger.LogInformation("Account deleted: {AccountId}", evt.AccountId);
+                
+                await using var transaction = await db.Database.BeginTransactionAsync(cancellationToken: stoppingToken);
+                try
+                {
+                    var files = await db.Files
+                        .Where(p => p.AccountId == evt.AccountId)
+                        .ToListAsync(cancellationToken: stoppingToken);
+
+                    await fs.DeleteFileDataBatchAsync(files);
+                    await db.Files
+                        .Where(p => p.AccountId == evt.AccountId)
+                        .ExecuteDeleteAsync(cancellationToken: stoppingToken);
+
+                    await transaction.CommitAsync(cancellationToken: stoppingToken);
+                }
+                catch (Exception)
+                {
+                    await transaction.RollbackAsync(cancellationToken: stoppingToken);
+                    throw;
+                }
+            }
+            catch (Exception ex)
+            {
+                logger.LogError(ex, "Error processing AccountDeleted");
+            }
+        }
+    }
+}