v1.2.0 - Workbook sanitizer for broken references

Fixes 'Specified argument was out of the range of valid values (Parameter id)' when comparing workbooks that contain broken drawing/image/hyperlink/table relationships or out-of-range style indices (common in xlsx files edited by third-party tools). Adds a safe workbook loader that repairs a temporary copy via OpenXML SDK before handing off to ClosedXML, without modifying the original files. Requires .NET 10 Desktop Runtime (win-x64).