Add support for running G-Cases

[andrewdnolan]

This PR hooks up the coupling channels needed to support G-cases. In order to support this, it:

• Calculates the running AvgNormalVeolcity and AvgSshGrad on edges for each ocean timestep (on the device). Reconstruction to cell centers, which still happens on device, occurs in OcnToCplFields::copyToHost‎. This prevents reconstruction happening every ocean timestep and instead happens only every coupling interval.
  • Reconstructed fields are then exported to the o2x_So_u/o2x_So_v and o2x_So_dhdx/o2x_So_dhdy coupler fields, respectively.
• Adds G-Case compset definitions to components/omega/cime_config/config_compsets.xml.
• Import the remaining x2o cpl fields (e.g. Foxx_swnet, Faxa_lwdn, ...) and applies those to the Forcing class.
• Converts (to first order) Omega's internal absolute salinity (g / kg) to practical salinity (psu), when exporting o2x_So_s to the coupler.
  • For details about a more accurate conversion, see Add an EOS helper function for TEOS10 conversion of AbsSalinty -> PracSalinity #467.

This PR is blocked by:

• Adds the thermo coupling  #461
  • Needed for apply forcing to thickness and tracer tendencies
• Add horizontal mesh operator for reconstructing edge-normal vector fields at cell centers #480
  • Needed to reconstruct normal velocity at edges to zonal/merid at cell centers (i.e. o2x_So_u and o2x_So_v).
• Refactor Omega's buildnml into a validated, testable omega_buildnml package #494
  • For easier configuration of omega.yml, including setting of config options that apply to all coupled simulations.

The branch used to open this PR has been rebased onto each of these PR. As these they are merged into develop, this branch should be rebased to remove the already merged commits.

---

Checklist

• Documentation:

  • Design document has been generated and added to the docs
  • User's Guide has been updated
  • Developer's Guide has been updated
  • Documentation has been built locally and changes look as expected

• Linting

  • Pre-commit run locally

• Building

  • CMake build does not produce any new warnings from changes in this PR

• Testing

  aurora, oneapi-ifx, mpich

  • CTests Pass
  • Polaris omega_pr Pass

  chrysalis, oneapi-ifx, openmpi

  • CTests Pass
  • Polaris omega_pr Pass

  frontier, craygnu, mpich

  • CTests Pass
  • Polaris omega_pr Pass

  frontier, craygnu-mphipcc, mpich

  • CTests Pass
  • Polaris omega_pr Pass

  pm-cpu, gnu, mpich

  • CTests Pass
  • Polaris omega_pr Pass

  pm-gpu, gnugpu, mpich

  • CTests Pass
  • Polaris omega_pr Pass

• Provide relevant details in a comment to the PR titled Testing with the following:

  • Which machines CTest unit tests
    have been run on and indicate that are all passing.
  • The Polaris omega_pr test suite
    has passed, using the Polaris e3sm_submodules/Omega baseline
  • Document machine(s), compiler(s), and the build path(s) used for -p for both the baseline (Polaris e3sm_submodules/Omega) and the PR build
  • Indicate "All tests passed" or document failing tests
  • Document testing used to verify the changes including any tests that are added/modified/impacted.

• Performance related PRs: Please include a relevant PACE experiment link documenting performance before and after.

• New tests:

  • CTest unit tests for new features have been added per the approved design.
  • Polaris tests for new features have been added per the approved design (and included in a test suite)

• Stealth Features

  • If any stealth features are included in the PR, please confirm that they have been documented.

[andrewdnolan]

Testing:

PEM_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu.20260811_171246_675kgd
    PASS PEM_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu CREATE_NEWCASE
    PASS PEM_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu XML
    PASS PEM_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu SETUP
    PASS PEM_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu SHAREDLIB_BUILD time=99
    PASS PEM_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu MODEL_BUILD time=208
    PASS PEM_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu SUBMIT
    PASS PEM_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu RUN time=685
    PASS PEM_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu COMPARE_base_modpes
    PASS PEM_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu MEMLEAK
    PASS PEM_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu SHORT_TERM_ARCHIVER

ERS_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu.20260811_155937_csm0bl
    PASS ERS_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu CREATE_NEWCASE
    PASS ERS_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu XML
    PASS ERS_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu SETUP
    PASS ERS_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu SHAREDLIB_BUILD time=93
    PASS ERS_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu MODEL_BUILD time=203
    PASS ERS_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu SUBMIT
    PASS ERS_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu RUN time=773
    PASS ERS_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu COMPARE_base_rest
    PASS ERS_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu MEMLEAK
    PASS ERS_Vmct.T62_oQU240.GOMEGA-IAF.frontier_craygnu SHORT_TERM_ARCHIVER

[cbegeman]

I just want to remind you that the SSH grad as produced by SSHGradOnEdge is not the right one for coupling. See https://github.com/E3SM-Ocean-Discussion/E3SM/pull/140/changes for the full gradient to use. If you want to replicate MPAS-O first, just include the SSH and sea ice pressure.