Add hierarchical workspace instructions

src/schema.rs

@@ -19,6 +19,7 @@ diesel::table! {
         content -> Text,
         model_content -> Nullable<Text>,
         tool_approval_reasons -> Nullable<Text>,
+        instruction_metadata -> Nullable<Text>,
         system -> Bool,
         compaction -> Bool,
         compaction_tail_start -> Nullable<Integer>,