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/views/executive.ejs

@@ -129,7 +129,7 @@
 		// trying the form out — make it a deliberate, confirmed action.
 		if (filterType === 'all' || filterType === 'all_active') {
 			const label = filterType === 'all' ? 'ALL users (including inactive)' : 'all ACTIVE users';
-			const confirmed = await app.util.actionConfirm(`Send this notification to ${label}?`, $compose, 'warning');
+			const confirmed = await app.messages.confirm(`Send this notification to ${label}?`, $compose, 'warning');
 			if (!confirmed) return;
 		}