fix: align dependency versions with Expo SDK 54

Packages were pinned to SDK 55 versions causing compatibility warnings
and potential runtime crashes:
  expo-notifications 55.x → 0.32.17
  expo-secure-store 55.x  → 15.0.8
  expo-task-manager 55.x  → 14.0.9
  @react-native-community/datetimepicker 9.x → 8.4.4

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

artifacts/postiz-mobile/package.json

@@ -56,11 +56,11 @@
     "zod-validation-error": "^3.4.0"
   },
   "dependencies": {
-    "@react-native-community/datetimepicker": "^9.1.0",
+    "@react-native-community/datetimepicker": "8.4.4",
     "axios": "^1.15.2",
-    "expo-notifications": "^55.0.22",
-    "expo-secure-store": "^55.0.13",
-    "expo-task-manager": "^55.0.15",
+    "expo-notifications": "~0.32.17",
+    "expo-secure-store": "~15.0.8",
+    "expo-task-manager": "~14.0.9",
     "react-native-calendars": "^1.1314.0"
   }
 }