feat(bd-2g50): fill data gaps in issue detail view

Add references_full, user_notes_count, merge_requests_count computed
fields to show issue. Add closed_at and confidential columns via
migration 023.

Closes: bd-2g50

src/core/db.rs

@@ -69,6 +69,10 @@ const MIGRATIONS: &[(&str, &str)] = &[
         "021",
         include_str!("../../migrations/021_work_item_status.sql"),
     ),
+    (
+        "023",
+        include_str!("../../migrations/023_issue_detail_fields.sql"),
+    ),
 ];
 
 pub fn create_connection(db_path: &Path) -> Result<Connection> {