Sessions could be archived from the sidebar row menu but never restored:
the registry-global archive set was a one-way display filter with no
inverse RPC and no surface listing its members.
WorkspaceRegistry.unarchiveSession drops one id from archivedSessionIds in
one durable write on the same operation chain as archive, with no
session-existence probe because a removal cannot introduce an unknown
referent. The Workspace controller exposes it as workspace.unarchiveSession
returning the complete archive set, which the existing archived follow
increment already propagates, so no frame type and no persisted field
changes.
The new client package dsh-client-ui-settings-unarchive-sessions owns the
restore surface: one localized settings.section page listing the archive
set joined with loaded session summaries, newest archive first, searchable
by title or workspace, with one Unarchive action per row.
imccyu