fix(mobile): render notes with marked (proper Markdown→HTML) + design CSS soigné

- Install marked package (UMD, hors-ligne)
- buildHtml: parse Markdown server-side avec marked, inject HTML statique
- CSS: typographie soignée, blockquotes brandés, code dark, tables propres
- Plus de CDN, fonctionne hors-ligne

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

memento-mobile/package.json

@@ -10,23 +10,24 @@
     "build:ios": "eas build --platform ios"
   },
   "dependencies": {
+    "@react-native-async-storage/async-storage": "2.2.0",
     "expo": "~54.0.35",
-    "expo-router": "~6.0.24",
-    "expo-status-bar": "~3.0.9",
-    "expo-secure-store": "~15.0.8",
-    "expo-font": "~14.0.12",
-    "expo-splash-screen": "~31.0.13",
-    "expo-linking": "~8.0.12",
     "expo-constants": "~18.0.13",
+    "expo-font": "~14.0.12",
+    "expo-linking": "~8.0.12",
+    "expo-router": "~6.0.24",
+    "expo-secure-store": "~15.0.8",
+    "expo-splash-screen": "~31.0.13",
+    "expo-status-bar": "~3.0.9",
+    "lucide-react-native": "^0.477.0",
+    "marked": "^18.0.4",
     "react": "19.1.0",
     "react-native": "0.81.5",
     "react-native-safe-area-context": "~5.6.0",
     "react-native-screens": "~4.16.0",
+    "react-native-svg": "15.12.0",
     "react-native-webview": "13.15.0",
-    "@react-native-async-storage/async-storage": "2.2.0",
-    "zustand": "^5.0.2",
-    "lucide-react-native": "^0.477.0",
-    "react-native-svg": "15.12.0"
+    "zustand": "^5.0.2"
   },
   "devDependencies": {
     "@babel/core": "^7.25.2",
@@ -34,4 +35,3 @@
     "typescript": "~5.9.2"
   }
 }
-