feat: finish the ai plugin (B18)

drizzle/postgres/0048_rare_catseye.sql

@@ -0,0 +1,8 @@
+-- The ai tables moved to the ai plugin, which renames them into its own
+-- namespace at activation, and ssh_data.enable_ai_assistant and the two
+-- user_preferences ai columns moved to its settings. Both run after this
+-- migration, so a real DROP here would delete the data first. The columns
+-- stay in place, unused, until 3.0.0. The timestamp and label type changes
+-- drizzle-kit also wrote are generator drift (see FINISH-LIST.md), not a
+-- change to the database, and are left out on purpose.
+SELECT 1;