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

Replaces the vendored app.util.actionMessage/actionConfirm/alert (the
latter added ad hoc to fix "app.util.alert is not a function") with the
published @simpleworkjs/frontend package: app.messages.action/confirm,
app.modal.open, and app.validate.js (which also replaces the identical
vendored val.js). Gains real HTML-escaping on message content and a toast
fallback when there's no inline .actionMessage target, neither of which
the vendored code had.

app.api/app.auth/app.pubsub/app.socket in app-base.js are untouched —
they're app-specific (dual-mode callback/promise API, auth-token header
injection) and not something the generic frontend package's app.js
provides, so it isn't loaded here.

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

nodejs/package.json

@@ -23,10 +23,11 @@
   "dependencies": {
     "@fortawesome/fontawesome-free": "^7.3.0",
     "@popperjs/core": "^2.11.8",
-    "@simpleworkjs/conf": "^1.2.0",
     "@simpleworkjs/app-stack": "^1.0.0",
-    "@simpleworkjs/ldap": "^1.0.0",
+    "@simpleworkjs/conf": "^1.2.0",
     "@simpleworkjs/directory-schema": "^1.0.0",
+    "@simpleworkjs/frontend": "^0.2.5",
+    "@simpleworkjs/ldap": "^1.0.0",
     "@simpleworkjs/orm": "^0.2.8",
     "bcrypt": "^6.0.0",
     "bootstrap": "^5.3.8",