Adopt @simpleworkjs/frontend's messages/modal/validate modules

Same swap as sso-manager-node/proxy: vendored app.util.actionMessage/
actionConfirm replaced by @simpleworkjs/frontend's app.messages.action/
confirm; vendored val.js replaced by the package's app.validate.js.
jump-host's views don't call actionMessage/actionConfirm/alert directly,
so no view changes are needed beyond the script includes.

app.api/app.auth/app.pubsub/app.socket in app-base.js are untouched, same
reasoning as the other two apps' PRs.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

nodejs/package.json

@@ -23,6 +23,7 @@
     "@simpleworkjs/app-stack": "^1.0.0",
     "@simpleworkjs/conf": "^1.2.0",
     "@simpleworkjs/directory-schema": "^1.0.0",
+    "@simpleworkjs/frontend": "^0.2.5",
     "@simpleworkjs/ldap": "^1.0.1",
     "@simpleworkjs/oidc-client": "^1.0.0",
     "@simpleworkjs/orm": "^0.2.8",