ci(coverage): remove || true test-masking (CLAUDE.md rule 12) (#130)

Per the audit at /tmp/ci-audit-2026-05-22.md, the coverage workflow's
test step was suppressing failures with `|| true` while still uploading
whatever partial coverage data accumulated. This made the workflow
report green even when tests failed silently — exactly the bug class
CLAUDE.md rule 12 calls out (shipped != verified).

Fix: drop `|| true`. Move codecov upload to `if: always()` so coverage
still uploads on test failures but the workflow conclusion now
reflects actual test status.

Co-authored-by: Claude <claude@anthropic.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: mastermanas805

.github/workflows/coverage.yml

@@ -20,7 +20,8 @@ jobs:
           node-version: 20
           cache: npm
       - run: npm ci
-      - run: npm test -- --coverage || true
+      - run: npm test -- --coverage
       - uses: codecov/codecov-action@v4
+        if: always()
         with:
           fail_ci_if_error: false