CLIP: Enter at the object prompt ends silently

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/command.rs

@@ -1943,7 +1943,8 @@ pub enum CmdResult {
         p1: DVec3,
         p2: DVec3,
     },
-    /// Print a measurement result to the command line and end the command.
+    /// Print a measurement result to the command line and end the command
+    /// (an empty one ends it silently).
     Measurement(String),
     /// Print a measurement result and keep the command active.
     ReportMeasurement(String),