Sungrow's OAuth server keeps only one active token session per (app,
account), not per plant -- with Kallangur and McDowall each managing their
own independent token against the same account, whichever one refreshed
last was silently invalidating the other's refresh token. Both instances
now share one token file (a common bind-mounted volume) instead of each
holding their own.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
