Fix CI lint failures on commongrid PR #344

BOLT-1856 / commongrid PR #344. Slava explicitly requested CI remediation. Inspect every current failure; make only valid, scope-contained lint/format/accessibility fixes directly on existing branch slava/fix-power-plant-substations. Run the relevant local checks, commit with the required Co-authored-by trailer, push, and monitor CI through green. Do not merge.