feat: replace password login with OIDC PKCE flow

package.json

@@ -12,8 +12,10 @@
   "dependencies": {
     "@maplibre/maplibre-react-native": "~11.0.0",
     "expo": "~54.0.33",
+    "expo-auth-session": "~7.0.11",
     "expo-background-fetch": "~14.0.9",
     "expo-constants": "~18.0.13",
+    "expo-crypto": "~15.0.9",
     "expo-document-picker": "~14.0.8",
     "expo-file-system": "~19.0.21",
     "expo-linking": "~8.0.11",
@@ -24,6 +26,7 @@
     "expo-status-bar": "~3.0.9",
     "expo-system-ui": "~6.0.9",
     "expo-task-manager": "~14.0.9",
+    "expo-web-browser": "~15.0.11",
     "react": "19.1.0",
     "react-dom": "19.1.0",
     "react-native": "0.81.5",