feat: add Plaid transaction handling and async queue processing

- introduced new migration to add Cursor column to AccountMetadata.
- updated AppDbContext model snapshot to reflect changes in the database schema.
- implemented async queue processing with ChannelAsyncQueue and AsyncQueueHostedService.
- created Plaid transaction handlers for added, modified, and removed transactions.
- developed PlaidTransactionService and PlaidTransactionSyncer for syncing transactions.
- added SyncUpdatesProcessor to handle sync updates from Plaid.
- updated tests to accommodate changes in institution and account metadata handling.

src/FiscalOS.Infra/Transactions/Plaid/PlaidTransactionProcessor.cs

@@ -0,0 +1,46 @@
+using Account = FiscalOS.Core.Accounts.Account;
+
+namespace FiscalOS.Infra.Transactions.Plaid;
+
+internal interface IPlaidTransactionProcessor
+{
+  Task ProcessAsync(
+    Account account,
+    TransactionsSyncResponse syncResponse,
+    CancellationToken cancellationToken
+  );
+}
+
+internal sealed class PlaidTransactionProcessor : IPlaidTransactionProcessor
+{
+  private readonly IPlaidAddedTransactionHandler _addedHandler;
+  private readonly IPlaidModifiedTransactionHandler _modifiedHandler;
+  private readonly IPlaidRemovedTransactionHandler _removedHandler;
+
+  private PlaidTransactionProcessor(
+    IPlaidAddedTransactionHandler addedHandler,
+    IPlaidModifiedTransactionHandler modifiedHandler,
+    IPlaidRemovedTransactionHandler removedHandler
+  )
+  {
+    _addedHandler = addedHandler;
+    _modifiedHandler = modifiedHandler;
+    _removedHandler = removedHandler;
+  }
+
+  internal static PlaidTransactionProcessor From(IServiceProvider provider)
+  {
+    return new(
+      provider.GetRequiredService<IPlaidAddedTransactionHandler>(),
+      provider.GetRequiredService<IPlaidModifiedTransactionHandler>(),
+      provider.GetRequiredService<IPlaidRemovedTransactionHandler>()
+    );
+  }
+
+  public async Task ProcessAsync(Account account, TransactionsSyncResponse syncResponse, CancellationToken cancellationToken)
+  {
+    _addedHandler.Handle(account, syncResponse.Added);
+    _modifiedHandler.Handle(account, syncResponse.Modified);
+    await _removedHandler.HandleAsync(syncResponse.Removed, cancellationToken).ConfigureAwait(false);
+  }
+}