Shows a small arrow next to the ticket count in each agent card header:
↑3 (orange) = received 3 more than resolved → backlog growing
↓2 (green) = resolved 2 more than received → backlog shrinking
Hidden when delta is 0 (stable).
Delta is computed from received_in_period (tickets created in the
selected period assigned to this agent) minus resolved_in_period.
No snapshot storage needed — derived from existing ticket data.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>