Prepare the mobile VM golden

Bootstrap needs the stopped opensteer-gui-golden and its existing SSH key; no new key is generated. Keep the source checkout clean.

1. Make a real, non-symlink input directory outside the checkout, holding only trusted licensed inputs as regular files: xcode.tar rooted at Xcode.app/, runtime.tar rooted at runtime.exportedBundle/ with the complete exported arm64 runtime, and manifest.json.

2. Archive Xcode:

   COPYFILE_DISABLE=1 tar -cf /absolute/inputs/xcode.tar -C /Applications Xcode.app
   

3. Export the runtime with Apple's supported command: