feat(scenarios): add detail page, comfortable DescriptionList layout, and environment card refactor

- Add ScenarioDetailPage with DescriptionList, steps table, run/delete actions
- Add /scenarios/:id route
- Add i18n keys for scenario detail fields, steps columns, and 404 error
- Add 'comfortable' and 'inline' layout variants to DescriptionList (with compact as default stacked)
- Apply layout="comfortable" to session, environment, and scenario detail pages
- Apply layout="compact" to EnvironmentsPage card DescriptionList
- Refactor EnvironmentsPage card to use ContextMenu (view/edit/delete) with icons
- Add ScenariosPage clickable rows, Play icon (primary) and Trash2 icon (danger) action buttons
- Add Page.module.css sectionHeading and stepsSection utility classes
- Fix Notification.tsx and Table.tsx formatting (prettier)

client/src/pages/SessionDetailPage.tsx

@@ -60,6 +60,7 @@ export function SessionDetailPage() {
       {session && (
         <Card>
           <DescriptionList
+            layout="comfortable"
             items={[
               { term: t('sessions.field_id'), detail: session.id },
               { term: t('sessions.field_name'), detail: session.sessionName },
@@ -71,7 +72,10 @@ export function SessionDetailPage() {
                   </Badge>
                 ),
               },
-              { term: t('sessions.field_token'), detail: <code className={styles.codeInline}>{session.token}</code> },
+              {
+                term: t('sessions.field_token'),
+                detail: <code className={styles.codeInline}>{session.token}</code>,
+              },
               {
                 term: t('sessions.field_lastUsed'),
                 detail: session.lastUsedAt ? <Timestamp value={session.lastUsedAt} /> : '—',