tl;dr

• thanks to @naaraxi, who did the entire work, authenticator-based 2FA has arrived.
• fixed a bug in cache disk numbering (thanks for reporting @rmnp30).
• renovated the options flow when editing the NAS.
• stabilized entity ID's / make the failure-proof against those ongoing HA Core changes.
• added further languages for setup & options flow: ja (jp), ko, zh-Hans (cn), zh-Hant (cn), nl, pt, sv, da, nb (no), fi.

Full story

👉 Added

• optional two-factor authentication support using authenticator app codes.
• trusted-device registration for UGOS accounts with 2FA enabled.
• a separate Advanced settings step to the integration options flow.
• new languages for setup & options flow: ja (jp), ko, zh-Hans (cn), zh-Hant (cn), nl, pt, sv, da, nb (no), fi.

👉 Changed

• unified normal login and 2FA enrollment to use the same internal authentication mechanism.
• moved polling intervals and example-dashboard settings out of the main options page.
• updated all included translations for the revised options flow.

👉 Fixed

• stabilized entity IDs for the Fan Mode and Power Mode selects.
• fixed example-dashboard compatibility with newly created mode-select entities.
• fixed cache-pool and cache-disk key parsing.
• fixed incorrect assignment of cache disks to the wrong pool or cache device.
• fixed incorrect cache-device names, metadata, and device hierarchy caused by the parsing error.

👉 Notes

• two-factor authentication currently supports authenticator app codes only, Email-based 2FA codes are not supported.