fix teacher, parent and admin pages

src/pages/emails/EmailTemplatePreviewPage.tsx

@@ -0,0 +1,34 @@
+import { Link, useParams } from 'react-router-dom'
+import { EmailPreviewLayout } from './EmailPreviewLayout'
+import { EMAIL_TEMPLATE_REGISTRY, isEmailTemplateSlug } from './emailTemplatesRegistry'
+
+export function EmailTemplatePreviewPage() {
+  const { templateId } = useParams<{ templateId: string }>()
+  const slug = templateId ?? ''
+
+  if (!isEmailTemplateSlug(slug)) {
+    return (
+      <div className="container py-4">
+        <div className="alert alert-warning">Unknown template: {slug}</div>
+        <Link to="/app/administrator/email-templates">Back to list</Link>
+      </div>
+    )
+  }
+
+  const entry = EMAIL_TEMPLATE_REGISTRY[slug]
+
+  return (
+    <div className="container-fluid py-3">
+      <div className="d-flex flex-wrap align-items-center gap-2 mb-3">
+        <Link to="/app/administrator/email-templates" className="btn btn-sm btn-outline-secondary">
+          ← All templates
+        </Link>
+        <h2 className="h5 mb-0">{entry.title}</h2>
+      </div>
+      <p className="small text-muted mb-3">
+        CI: <code>{entry.ciView}</code>
+      </p>
+      <EmailPreviewLayout>{entry.render()}</EmailPreviewLayout>
+    </div>
+  )
+}