docs: Document current Expo architecture for native migration

- Document technology stack (Expo, TypeScript, Zustand, SQLite)
- Map out all data models and types
- Document service dependencies and architecture
- Create component dependency diagrams
- Document data flow for feed sync and search
- Provide migration checklist with priorities
- Identify pure TypeScript vs native-dependent services

This analysis provides the foundation for migrating business logic
from Expo/TypeScript to native platforms (iOS, Android, Linux).

package.json

@@ -17,6 +17,8 @@
     "@react-navigation/native": "^7.1.33",
     "@tanstack/react-query": "^5.95.2",
     "axios": "^1.14.0",
+    "buffer": "^6.0.3",
+    "events": "^3.3.0",
     "expo": "55.0.10-canary-20260328-2049187",
     "expo-constants": "55.0.10-canary-20260328-2049187",
     "expo-device": "55.0.11-canary-20260328-2049187",
@@ -34,6 +36,7 @@
     "expo-system-ui": "55.0.12-canary-20260328-2049187",
     "expo-task-manager": "55.0.11-canary-20260328-2049187",
     "expo-web-browser": "55.0.11-canary-20260328-2049187",
+    "fast-xml-parser": "^5.5.9",
     "react": "19.2.0",
     "react-dom": "19.2.0",
     "react-native": "0.83.4",
@@ -44,7 +47,7 @@
     "react-native-screens": "~4.23.0",
     "react-native-web": "~0.21.0",
     "react-native-worklets": "0.7.2",
-    "xml2js": "^0.6.2",
+    "stream-browserify": "^3.0.0",
     "zustand": "^5.0.12"
   },
   "devDependencies": {