Fix summation errors in CO2 land use also for coupled runs

[dklein-pik]

Purpose of this PR

This is a follow-up to #2389 that corrected the fixing to a reference runs for p_co2lucSub. However, the fix only worked for standalone runs. This PR corrects the fixing also for coupled runs.

Important note: this fix is only about p_co2lucSub, which is a parameter that is only passed through REMIND to the reporting. The wrong fixing did not have any impact on the optimization.

Type of change

Parts concerned

• ☑️ GAMS Code
• ◻️ R-scripts
• ◻️ Documentation (GAMS incode documentation, comments, tutorials)
• ◻️ Input data / CES parameters
• ◻️ Tests, CI/CD (continuous integration/deployment)
• ◻️ Configuration (switches in main.gms, default.cfg, and scenario_config*.csv files)
• ◻️ Other (please give a description)

Impact

• ☑️ Bug fix
• ◻️ Refactoring
• ◻️ New feature
• ◻️ Change of parameter values or input data (including CES parameters)
• ◻️ Minor change (default scenarios show only small differences)
• ◻️ Fundamental change of results of default scenarios

Checklist

• I executed the automated model tests (make test) after my final commit and all tests pass (FAIL 0)
• I adjusted the reporting in remind2 if and where it was needed
• I adjusted the madrat packages (mrremind and other packages involved) for input data generation if and where it was needed
• My code follows the coding etiquette
• I explained my changes within the PR, particularly in hard-to-understand areas
• I checked that the in-code documentation is up-to-date
• I adjusted forbiddenColumnNames in readCheckScenarioConfig.R in case the PR leads to deprecated switches
• I updated the CHANGELOG.md correctly (added, changed, fixed, removed, input data/calibration)

[Copilot]

Pull request overview

This PR adjusts how p_co2lucSub (CO2 land-use subcategories passed through for reporting) is populated in coupled REMIND–MAgPIE runs so that values for years before cm_startyear remain consistent with the fixing/reference mechanism (as already implemented for standalone runs in #2389).

Changes:

• Restrict the coupled-run overwrite of p_co2lucSub in core/presolve.gms to only affect years ≥ cm_startyear.
• Clarify comments in core/datainput.gms around when p_co2lucSub is loaded from input_ref.gdx vs. overwritten from lookup/coupling sources.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
core/presolve.gms	Limits coupled-run overwrite of p_co2lucSub to years ≥ cm_startyear (to avoid breaking fixing for earlier years).
core/datainput.gms	Comment clarification about p_co2lucSub being loaded from input_ref.gdx and overwritten for years ≥ cm_startyear.

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[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

[LaviniaBaumstark]

nice, thanks