Parser audit verification

Workflow runs for Parser audit verification

• ci: verify parser fixes, cross-protocol state, and acceptance gates

  failed:
  Parser audit verification#3:Commitc8d8eebpushedbysimota
  audit/parser-boundary-fixes-20260915

  Sep 15, 202633m 17s
  More actions for workflow run 3

• ci: install protoc and prove parser regressions before fixes

  completed successfully:
  Parser audit verification#2:Commit4d41806pushedbysimota
  audit/parser-boundary-fixes-20260915

  Sep 15, 20263m 15s
  More actions for workflow run 2

• ci: record isolated parser audit baseline

  failed:
  Parser audit verification#1:Commit49fd333pushedbysimota
  audit/parser-boundary-fixes-20260915

  Sep 15, 20261m 19s
  More actions for workflow run 1