Add date range picker and download button to the dashboard page, backed by GET /dashboard/export endpoint that returns a StreamingResponse CSV file. Completes Phase 4 (final V2 improvement). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add date range picker and download button to the dashboard page, backed by GET /dashboard/export endpoint that returns a StreamingResponse CSV file. Completes Phase 4 (final V2 improvement). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>