geometry: defeature a design by suppressing its features, virtually when they cannot be

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo

crates/geometry/src/partition.rs

@@ -178,6 +178,7 @@ impl Design {
             source: std::sync::Arc::clone(&self.source),
             opened: std::sync::Arc::clone(&self.source),
             history: self.history.clone(),
+            defeat: self.defeat.clone(),
         })
     }
 }