fix(ci): add Node 18 skip condition for c8 v11 coverage step

c8 v11 requires Node 20+ (engines: ^20.0.0 || >=22.0.0).
Node 18 now runs plain npm test on PRs to avoid engine mismatch.
Also removes redundant --exclude flag from test:coverage script.

Also: fix ROADMAP.md progress table alignment (rows 7-12), mark
Phase 7 complete, add requirements-completed to 09-01-SUMMARY.md.

.github/workflows/test.yml

@@ -41,5 +41,10 @@ jobs:
         run: npm test
 
       - name: Run tests with coverage
-        if: github.event_name == 'pull_request'
+        # c8 v11 requires Node 20+ (engines: ^20.0.0 || >=22.0.0). Node 18 EOL April 2025.
+        if: github.event_name == 'pull_request' && matrix.node-version != 18
         run: npm run test:coverage
+
+      - name: Run tests (Node 18, coverage not supported)
+        if: github.event_name == 'pull_request' && matrix.node-version == 18
+        run: npm test