* [MM-68736] Reconcile partial GM membership in bulk import importDirectChannel failed with "ChannelMember not found" when the group channel hash already existed in Channels but one or more participants were missing from ChannelMembers (concurrent import workers, a prior import that crashed mid SaveMember loop, or a pre-existing GM whose membership has drifted). The function only used existingMembers to compare LastViewedAt and still appended absent participants to UpdateMultipleMembers, whose UPDATE-then-SELECT returns sql.ErrNoRows for the missing row. Insert the missing ChannelMembers row via SaveMember (logging the join event) before the UPDATE path. ErrConflict is treated as benign so concurrent workers racing on the same MPIM hash do not fail each other. * [MM-68736] Add missing i18n key for new bulk import error The save_member.error key was added in the importDirectChannel fix but not registered in i18n/en.json. * [MM-68736] Address review feedback - Broaden the save_member.error translation to also cover DM imports, since importDirectChannel runs the same SaveMember reconciliation path for both 2-participant DMs and 3+-participant GMs. - In the idempotent re-import test, assert that ChannelMemberHistory.GetMembershipChanges returns no rows after the second import. LogJoinEvent is only invoked when the missing-member branch runs, so an empty result proves SaveMember was not called for any already-present participant.
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