Work already complete. The E2E tests for 'Update milestone status to in-progress' exist in tests/e2e/test_update_milestone_status_to_in_progress.py (182 lines, 3 test methods): 1. test_update_milestone_status_from_planned_to_in_progress 2. test_update_milestone_status_from_complete_to_in_progress 3. test_update_milestone_status_from_archived_to_in_progress These tests were added in commit d850063 (attributed to TRCKR-640). The tests verify: - Creating a project and milestone via API - Navigating to projects page and opening project detail modal - Changing milestone status using inline dropdown - Verifying changes persist via API No additional work needed - the tests are complete and match the issue requirements.