Clamp Stratum version rolling mask to ASIC capability

[0xjc65eth]

Summary

• advertise the ASIC-supported version rolling mask instead of the hardcoded ffffffff Stratum V1 mask
• add an ASIC helper for the supported version rolling mask
• clamp pool-provided mining.set_version_mask / mining.configure results before storing them globally

Fixes #1169

Testing

• git diff --check

Firmware build was not run because idf.py is not installed in this environment.

[0xjc65eth]

Closing this for now to reduce maintainer review load, per feedback from @mutatrum. I am keeping #1705 open as the single focused PR because it is small, UI-only, and already has an ack. Happy to revisit this later only if maintainers ask for it. Thanks for the feedback and for maintaining the project.