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.API/Accounts/Add/Request.cs

@@ -5,9 +5,6 @@ public record Request : IValidatableObject
   public string PlaidInstitutionId { get; init; } = string.Empty;
   public string PlaidAccountId { get; init; } = string.Empty;
   public string PlaidAccountName { get; init; } = string.Empty;
-  public decimal AccountCurrentBalance { get; init; }
-  public decimal AccountAvailableBalance { get; init; }
-  public string AccountCurrencyCode { get; init; } = string.Empty;
 
   public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
   {
@@ -28,11 +25,5 @@ public record Request : IValidatableObject
       var fieldName = nameof(PlaidAccountName);
       yield return new($"The {fieldName} field is required.", [fieldName]);
     }
-
-    if (string.IsNullOrWhiteSpace(AccountCurrencyCode))
-    {
-      var fieldName = nameof(AccountCurrencyCode);
-      yield return new($"The {fieldName} field is required.", [fieldName]);
-    }
   }
 }