The CLI reference, the configuration guide and the set_config_value
docstring still said that any unknown path under a known section is
refused with a did-you-mean. After b47f40e699 only a path whose suffix is
itself a known key (gateway.discord.foo -> discord.foo) is refused; every
other unknown path under a known section — a same-section typo or an
unseeded runtime-read key — is written with a did-you-mean notice, because
DEFAULT_CONFIG is an incomplete schema and cannot tell the two apart.
Reword all three sites to state the refusal that actually exists and the
write-with-notice fallback, so users are not told a typo will be blocked.
f537076738