feat(client): set dynamic page title based on content

- add usePageTitle hook that writes '<title> | Liqa' to document.title
- list pages use section name; detail pages use entity name once loaded
- create/edit pages use static action title, edit includes entity name

client/src/pages/scenario/CreateScenarioPage.tsx

@@ -1,6 +1,7 @@
 import { useEffect, useState, SubmitEvent } from 'react';
 import { useNavigate } from 'react-router-dom';
 import { useTranslation } from 'react-i18next';
+import { usePageTitle } from '../../hooks/usePageTitle';
 import { X, Save, ClipboardList } from 'lucide-react';
 import { scenarios, environments } from '../../api';
 import type { Environment } from '../../api';
@@ -9,6 +10,7 @@ import styles from '../Page.module.css';
 
 export function CreateScenarioPage() {
   const { t } = useTranslation();
+  usePageTitle(t('scenarios.create_title'));
   const navigate = useNavigate();
   const toast = useToast();