The OCC report plans a station lane per cargo type — Nagad–Mojo container
and Nagad–Mojo fertilizer are separate numbers — but a target's identity
was period + metric + dimension + dimensionKey, so the two collided on
one slot. `cargo_category` is now part of the row and of the uniqueness
check; it stays null for cargo_category and container_class targets,
whose dimensionKey already carries the category.
The config grid showed raw codes (VOLUME_TONS, cargo_category, a yard
code). The list read now sends readable twins alongside the stored codes,
which stay exactly as they are because the reports join on them — the
same shape YardDistancesService uses. Labels resolve per dimension rather
than from one merged map: CONTAINER_EXPORT exists in both vocabularies
and reads differently in each, and merging them gave every cargo-category
row the container-class wording.
