add Quest hand tracking support and update docs

- Add hand tracking manifest entries to MosisSDK_UPL.xml
  - oculus.software.handtracking feature (required=false)
  - horizonos.permission.HAND_TRACKING permission
- Add OculusXR hand tracking settings to DefaultEngine.ini
- Update README with OBB deployment instructions and Quest config

Plugins/MosisSDK/Source/MosisSDK/MosisSDK_UPL.xml

@@ -5,6 +5,8 @@
       <queries>
         <package android:name="com.omixlab.mosis" />
       </queries>
+      <uses-feature android:name="oculus.software.handtracking" android:required="false" />
+      <uses-permission android:name="horizonos.permission.HAND_TRACKING" />
     </addElements>
   </androidManifestUpdates>
   <proguardAdditions>