feat: rebuild workspaces as the reference plugin

drizzle/mysql/0031_nebulous_diamondback.sql

@@ -0,0 +1,5 @@
+-- user_workspaces moved to the workspaces plugin, whose first migration renames it
+-- to p_workspaces_workspaces. Dropping it here would lose every saved workspace,
+-- so this only stops drizzle tracking it. SELECT 1 because MySQL rejects an
+-- empty query.
+SELECT 1;