v0.1.2

Added

• Error backoff per domain: after a failed update, retries are paused
  • abuse → 15 min, badauth / notfqdn → 30 min, dnserr / badsys / 911 → 5 min, other errors → 2 min
• Error sensor stays ON during backoff (last known error is preserved)
• retry_after attribute on the resolved-IP sensor when a domain is in backoff
• Update Now button bypasses backoff for an immediate forced retry