Avoid error displaying object when var added w/sparse dim arg.

Author: rdzman

CHANGES.md

@@ -5,6 +5,10 @@ Change history for MP-Opt-Model
 since version 5.0
 -----------------
 
+#### 10/3/25
+  - Avoid error displaying `mp.opt_model` object when variable was added
+    with a sparse dimension argument.
+
 #### 9/25/25
   - Improve reliability of detection of CLP MEX file.
 

lib/+mp/set_manager.m

@@ -273,10 +273,10 @@
 
             %% handle input args
             if iscell(idx)
-                N = varargin{1};
+                N = full(varargin{1});
                 args = varargin(2:end);
             else
-                N = idx;
+                N = full(idx);
                 idx = {};
                 args = varargin;
             end