Description

Long-running Excel/Word generation cannot be cancelled gracefully.

Location

Reporting/ReportGenerationService.cs

Tasks

• Add CancellationToken parameter to all report generation methods
• Check cancellation between major operations
• Update tests to verify cancellation behavior
• Update Program.cs to pass cancellation token
• Clean up partial files if cancelled

Acceptance Criteria

• All public report methods accept CancellationToken
• Cancellation is checked at appropriate intervals
• Partial files are cleaned up on cancellation
• Tests verify cancellation works correctly