Rate-limit responses from the CA now use the Retry-After hint (via client/local.RateLimitRetryAfter) instead of walking the local retry schedule. Failures that never reached the CA -- context deadline/cancel, ECONNREFUSED, ECONNRESET, EHOSTUNREACH, EPIPE, and net.Error timeouts -- retry at retrySchedule[0] without advancing retryCount. Updates tailscale/corp#42164 Signed-off-by: chaosinthecrd <tom@tmlabs.co.uk>