fix(release): Restore web-app install for npm publish

Install apps/web-app dependencies in the publish workflow before the\nfrontend build so CI matches the working Pages pipeline.\n\nHarden the maintainer release suite by adding the same install step\nbefore app:build, and switch the shared app:install helper to npm ci\nfor deterministic installs.\n\nDocument the follow-up patch release in the changelog so 8.7.1 can\npublish the 8.7.x line to npm after the 8.7.0 release failed before\nreaching the registry.

.github/workflows/publish-npm.yml

@@ -48,6 +48,9 @@ jobs:
       - name: Run docs security checks
         run: npm run security:docs
 
+      - name: Install web-app dependencies
+        run: npm run app:install
+
       - name: Build web app
         run: npm run app:build