Stage owned tvOS game data from guest SMB

[joeblack2k]

Summary

• add a read-only guest SMB wrapper around the existing game preparation and tvOS staging scripts
• select GMSE01 by disc header, copy it locally, and rely on the existing SHA-256 validation before staging
• keep server addresses, credentials, ROMs, and extracted data out of the repository

Verification

• ./scripts/check-repository.sh
• live read-only guest mount against the requested SMB server and discovery of Super Mario Sunshine (USA).iso
• invalid non-SMB input fails with usage status 64

[chrissotraidis]

Thank you for putting this together and for documenting the environment that motivated it. After reviewing it against the maintained tvOS workflow, I’m not incorporating this helper. A guest-only, read-only SMB mount with a fixed share convention is useful for a particular test setup, but it adds network- and environment-specific behavior that SunPad does not need to own. The supported path remains local preparation with prepare-game.sh, validated CoreDevice staging with stage-tvos-game-data.sh, and the existing backup helper. That keeps setup simple and avoids implying network-hosted game data support. I’m closing this PR without merging; this is a product-scope decision, not a dismissal of the investigation.