DiscordAdapter.connect() set self._running = True directly instead of
calling self._mark_connected(), unlike every other platform adapter
(Telegram, WeCom, Matrix, Feishu, Google Chat, IRC, LINE, Mattermost,
ntfy, photon, raft, simplex, a2a, buzz, dingtalk, whatsapp).
_mark_connected() clears _fatal_error_code/_fatal_error_message/
_fatal_error_retryable and rewrites the runtime status file as
"connected". Bypassing it meant a transient connect failure (e.g. a
one-off DNS blip: "Cannot connect to host discord.com:443 ssl:default
[Temporary failure in name resolution]") left the platform reported as
permanently fatal in gateway_state.json / the dashboard, even after the
adapter successfully reconnected and was actively serving messages for
hours.
Reproduced under gateway.multiplex_profiles: true with a secondary
profile's Discord bot (sarathi:discord) — the bot reconnected
repeatedly ("Connected as ..." logged many times over 18+ hours) while
the dashboard kept showing the original fatal error the entire time.
Fixes#102554.
Added a regression test asserting connect() clears a previously
recorded fatal error.
ec11359b44