Contest QSOs do not move the main DX target marker

[s53zo]

Summary

When the Contest QSOs map layer is enabled, newly received N1MM/DXLog QSOs are drawn as markers/arcs on the map, but the main DX target marker does not move to the latest worked station.

Impact

This leaves the dashboard in an inconsistent state:

• the contest overlay shows the latest QSO location
• the main DX target marker still points to an older/manual target
• propagation, beam heading, and DX weather panels continue using the stale DX target

Reproduction

1. Enable N1MM/DXLog QSO ingestion and log contest QSOs with valid lat/lon resolution.
2. Enable the Contest QSOs layer.
3. Log a new QSO.
4. Observe that the contest arc/marker appears, but the main DX target marker does not update.

Expected behavior

The latest contest QSO with valid coordinates should update the main DX target, while still respecting the existing DX lock behavior.

Notes

The current contest layer only renders overlay geometry. It does not have access to the app-level DX target update callback, so it cannot move the shared DX target state.