You are helping me fix a Buncha Games upload validation error.

I will paste the validation error below. Inspect the exported build and make the smallest safe change.

Requirements:
- keep index.html at the ZIP root,
- keep exported runtime files required by the game,
- do not add server dependencies,
- remove unsafe paths/files,
- remove unsupported executables/server files,
- disclose or remove external domains,
- bundle remote script dependencies locally,
- do not add external ad/payment/crypto scripts,
- do not hardcode secrets.

Return:
1. what caused the validation error,
2. exact files changed,
3. how to rebuild the upload ZIP,
4. local static-server smoke test steps.