Found a copy-paste typo, fixed it. stmtPostNew -> stmtCategoryNew.

pkg/mindflow/database/sqlite/db.go

@@ -192,7 +192,7 @@ func (s *SQLiteMindflow) NewCategory(name string) (int64, error) {
 	}
 	defer tx.Rollback()
 
-	r, err := tx.Stmt(stmtPostNew).Exec(name)
+	r, err := tx.Stmt(stmtCategoryNew).Exec(name)
 	if err != nil {
 		return 0, err
 	}