Treat auth refresh responses 400, 401, and 415 as terminal authentication failures
Clear stale auth state and refresh nonce, then immediately redirect to /login.html
Stop reconnect countdown/retry when terminal refresh failure is detected
Preserve normal retry behavior for transient failures such as 503
Add Playwright regression tests covering:
415 refresh failure redirects to login without runaway retries
503 refresh failure keeps retry behavior and does not force login redirect
adnit
721c1c96fe