The WS reconnect loop had a fallback check that looked for "401", "403",
or "unauthorized" as substrings anywhere in an exception's string form.
A transient error whose message happens to contain those digits (a proxy
body, a stack trace, anything) got treated as a permanent auth failure
and stopped reconnection for good.
I removed the substring fallback and kept only the structured check:
aiohttp.WSServerHandshakeError with status in {401, 403}. That's the only
signal that reliably means the server rejected our credentials.
Added two regression tests: one proving a transient error containing
"401" in its text still retries, and one confirming the existing
_closing early-return path is untouched by the removal.
Stephen Chin
d184d68f37