[WeiAi-Energy]

Closes #860.

Changes proposed in this Pull Request

• build_cost_data no longer reads AEO2023 from PUDL.
  • It reads the AEO2026 Table 3 electric power prices of natural gas, steam coal and distillate fuel oil from the EIA API (eia.ProjectedFuelCost).
  • The prices are converted from 2025$/MMBtu to 2023$/MWh_th.
  • Years outside 2025-2050 take the nearest year.
  • PUDL's AEO2026 table holds nominal prices only.
• costs: aeo: scenario takes the AEO2026 cases. reference is the Counterfactual Baseline, so existing configs, including the equivalence configs, still validate.
• The rule passes the EIA API key. The schema, default config comment and config table are updated.

Which plants these costs reach is unchanged here (see #861 / the follow-up PR).

Testing

• test_aeo_fuel_costs.py (6 tests): the API request, the AEO2026 cases, the 2023$ conversion, the nearest year and the unit check.
• pytest -m fast (this commit alone): 1000 passed, 11 skipped, 4 failed. The 4 failures also fail on develop: the three GoDEEEP CF registry tests and test_dag_dryrun.py::test_interface_limits_input_follows_config_key.

Checklist

• I tested my contribution locally and it seems to work fine.
• pre-commit and pytest -m fast pass locally.
• Code and workflow changes are sufficiently documented.
• Changed dependencies are added to workflow/envs/environment.yaml.
• Changes in configuration options are added in workflow/repo_data/config/config.default.yaml.
• Changes in configuration options are also documented in docs/source/configtables/*.csv.

🤖 Generated with Claude Code

[WeiAi-Energy]

Its commit was included in #864, which was squash-merged into develop as e261323, so nothing is left to merge here.