When a Slack bot is removed from a workspace while still configured in
OpenClaw, the gateway enters an infinite retry loop on account_inactive
or invalid_auth errors, making the entire gateway unresponsive.
Add isNonRecoverableSlackAuthError() to detect permanent credential
failures (account_inactive, invalid_auth, token_revoked, etc.) and
throw immediately instead of retrying. This mirrors how the Telegram
provider already distinguishes recoverable network errors from fatal
auth errors via isRecoverableTelegramNetworkError().
The check is applied in both the startup catch block and the disconnect
reconnect path so stale credentials always fail fast with a clear error
message.
Closes#32366
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
