Add bounded pagination and date-range limits to report endpoints #594

Problem

Several report requests accept arbitrary date ranges and return list-shaped responses without a maximum size. Some report logic materializes large transaction sets before calculating summaries, which can cause high memory usage and slow requests.

Relevant areas:

• EstateReportingAPI.DataTrasferObjects/TransactionDetailReportRequest.cs
• EstateReportingAPI.DataTrasferObjects/TransactionMixSummaryRequest.cs
• EstateReportingAPI.BusinessLogic/ReportingManager.cs

Scope

Define shared report-query limits and apply them consistently:

• Maximum report date range.
• Maximum page size.
• Maximum filter-list sizes.
• Maximum TopN.
• Stable ordering for paginated results.
• Server-side aggregation where possible.

Return a clear validation response when limits are exceeded.

Acceptance criteria

• Every potentially large report has an explicit bounded result strategy.
• Page size and TopN cannot be used to request unbounded data.
• Date-range and filter limits are covered by unit and integration tests.
• Transaction mix summaries do not load the entire detail result set unnecessarily.