feat(mobile): fondation design system DSFR (theme + composants UI) + hooks admin + route admin

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

mobile/components/ui/SectionTitle.tsx

@@ -0,0 +1,19 @@
+import { StyleSheet, Text } from 'react-native';
+import { Colors } from '@/lib/colors';
+import { FontSize, FontWeight, Spacing } from '@/lib/theme';
+
+/** Intitulé de section (petites capitales DSFR) au-dessus d'une liste/groupe. */
+export default function SectionTitle({ children }: { children: string }) {
+  return <Text style={styles.title}>{children}</Text>;
+}
+
+const styles = StyleSheet.create({
+  title: {
+    fontSize: FontSize.xs,
+    fontWeight: FontWeight.bold,
+    color: Colors.gray[500],
+    textTransform: 'uppercase',
+    letterSpacing: 1,
+    marginBottom: Spacing.sm,
+  },
+});