refactor: rename namespace to FiscalFlow and upgrade to .NET 10

- Rename InvoiceMaster.* to FiscalFlow.* namespace
- Upgrade from .NET 8 to .NET 10
- Update all NuGet packages to latest versions
- Update C# language version to 14.0

backend/src/FiscalFlow.Application/DTOs/InvoiceDtos.cs

@@ -0,0 +1,66 @@
+using FiscalFlow.Core.Entities;
+
+namespace FiscalFlow.Application.DTOs;
+
+public record InvoiceListItemDto(
+    Guid Id,
+    string Status,
+    string Provider,
+    string FileName,
+    string? SupplierName,
+    decimal? AmountTotal,
+    DateTime? InvoiceDate,
+    VoucherInfoDto? Voucher,
+    DateTime CreatedAt);
+
+public record VoucherInfoDto(
+    string? Series,
+    string? Number,
+    string? Url);
+
+public record InvoiceDetailDto(
+    Guid Id,
+    string Status,
+    string Provider,
+    FileInfoDto File,
+    ExtractionDataDto Extraction,
+    SupplierMatchDto? SupplierMatch,
+    VoucherPreviewDto? VoucherPreview,
+    DateTime CreatedAt);
+
+public record FileInfoDto(
+    string Name,
+    long? Size,
+    string Url);
+
+public record ExtractionDataDto(
+    string? SupplierName,
+    string? SupplierOrgNumber,
+    string? InvoiceNumber,
+    DateTime? InvoiceDate,
+    DateTime? DueDate,
+    decimal? AmountTotal,
+    decimal? AmountVat,
+    int? VatRate,
+    string? OcrNumber,
+    string? Bankgiro,
+    string? Plusgiro,
+    string Currency,
+    decimal? Confidence);
+
+public record SupplierMatchDto(
+    string Action,
+    string? SupplierNumber,
+    string? SupplierName,
+    decimal? Confidence);
+
+public record VoucherPreviewDto(
+    string? Series,
+    List<VoucherRowDto> Rows);
+
+public record VoucherRowDto(
+    int Account,
+    string? AccountName,
+    decimal Debit,
+    decimal Credit,
+    string? Description);