Warn when ASIC hash domains stop incrementing

[0xjc65eth]

Summary

• detect stalled ASIC hash domains from the existing per-domain hash counter registers
• expose stalled domain flags through the system info API and OpenAPI schema
• show an AxeOS warning and highlight stalled domains in the hashrate register card

Why

Issue #1053 reports devices that continue receiving pool work while one or more ASIC domains stop producing useful work. A previous recovery-only approach was rejected because it hid likely power/voltage/frequency problems behind automatic restarts. This PR adds direct observability first: the firmware reports the stalled domain so users can diagnose power supply, voltage, and frequency settings instead of only seeing a flatline.

Fixes #1053.

Testing

• npm run build
• git diff --check

Full firmware build was not run locally because idf.py is not installed in this shell and the Docker daemon is not running.

[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.