River sequence problems

[MartinDix]

Suites are currently using ancillaries from /scratch/tm70/kr4383/cylc-run/ancil-gen-22-04-2026/share/data/n96e_mom025_20260316 and
/scratch/tm70/kr4383/cylc-run/ancil-gen-22-04-2026/share/data/n96e_mom025_20260316/qrparm.landfrac.

The qrparm.rivseq files here have some blocked outflow points which is likely affecting water balance. They're also missing the Black Sea - Mediterranean connection

Unfortunately at the moment it's a manual correction for these. See also #48.

[anton-seaice]

Might be able to use remapping weights like

https://github.com/ACCESS-NRI/om3-scripts/blob/main/mesh_generation/generate_rof_weights.py

to ensure all runoff gets moved into the ocean (as long as the runoff reaching the mediator isn't lost to a land mask)