eventhub/README_CVU_FINAL_MERGE_PATCH.md

CVU final merge safeguard

Problem

After cross-representation CVU reconciliation the supplied mixed execution still contained 12 effective vehicle-usage intervals instead of 11. The remaining pair represented the same usage period:

• file-session CVU: 2026-03-31T00:00:00Z to 2026-04-02T12:27:15Z, registration present, VIN missing;
• database CVU: 2026-04-01T00:00:00Z to 2026-04-02T12:27:15Z, same registration, VIN present.

The final DriverVehicleUsageMergeModule required exact vehicleKey equality, so null and the database VIN prevented coalescing even though registration and overlap proved compatible identity.

Fix

DriverVehicleUsageMergeModule now:

• accepts complementary vehicle identity when registration or VIN matches and the other field is missing;
• merges overlapping as well as immediately adjacent effective intervals;
• rejects explicit registration/VIN conflicts;
• rejects materially conflicting odometers at identical boundaries;
• selects the richer interval as identity primary;
• preserves the earliest start, latest end, correct boundary odometers, and complete source provenance;
• reports coalescedIntervalCount metadata.

This is a generic final-interval safeguard and does not depend on tachograph representation enums.

Expected supplied-data result

• vehicle usage intervals: 12 -> 11
• VU card-absent intervals: remains 10
• support geo events: remains 141