- Widen the permanent-rejection match to the exact relay phrasings seen in
production (#97502): 'not a channel member' and 'auth-required', alongside
'restricted'.
- Close the re-adoption hole called out in review: _discover_dms() (both the
dms-list path and the channels-list fallback) now skips channels in
_restricted_channels, so a restricted channel dropped at runtime cannot be
silently re-added by the next discovery sweep and re-trigger the rejection.
- Credit: runtime CLOSED matching terms from PR #97502 by @repfigit; the
per-subscription drop + restricted set is PR #76850 by @xozai.
b907b7eb85