The route proxy also refuses with 'routing busy — too many routes at once'
(429) and 'route proxy error'; both showed in English in every locale.
Mark them in ROUTING_REFUSALS and add es, ru, zh-CN and zh-Hant entries.
errorText is now cleared on a new connection, a mode switch and stop(), so
it never outlives the error it describes. Tests cover the two refusals,
'Routing failed: rate limited' (pattern order) and the stop() reset.
Said Turksever