test(windows): enforce native coverage

.github/workflows/ci.yml

@@ -302,7 +302,7 @@ jobs:
 
   # One standard Windows box shares setup across the required build/site checks
   # and the observational portability inventory. Serial worker bounds keep this
-  # recovery path portable; Linux owns duplicate lint, coverage, and snapshots.
+  # recovery path portable; Linux owns duplicate lint and snapshots.
   # See the native-Windows pull-request CI decision:
   # .agents/notes/implemented/process/2026-08-08-native-windows-pull-request-ci.md
   windows:
@@ -310,6 +310,7 @@ jobs:
     runs-on: windows-2025
     name: windows node 24 / native complete
     env:
+      DSH_COVERAGE_MAX_WORKERS: '4'
       DSH_GATE_CONCURRENCY: '1'
       DSH_PUBLINT_CONCURRENCY: '1'
     steps: