- Validation now distinguishes blocking errors from warnings; only errors block submission, warnings are shown but allow progress.
- Introduced EkaerSeverity, EkaerValidationMessage, and severity-aware extensions for validation results.
- Extended EkaerHistory.Status with GeneratedWithWarning and SentWithMissingData; added EkaerStatusExtensions for status categorization.
- Added EkaerHistoryFilter for server-side filtering; updated SignalR and controller interfaces accordingly.
- UI now displays error/warning messages with color/icons, supports new status tabs/filters, and restricts XML copying to submittable records.
- Refactored validation and error handling to use new severity logic; updated comments and minor code for clarity.