fix(cli): preserve target order in summaries

Final multi-target summaries were printed by iterating the label-keyed
BTreeMap directly, so they came out in lexicographic label order
instead of the order targets were given on the command line. Iterate
setup.targets (the canonical prepared CLI order) instead, looking up
each target's stats by label, and keep the BTreeMap only for
event-time lookup.

crates/irtt-cli/src/cmd/client/run.rs

@@ -176,15 +176,18 @@ pub fn run_stream(
     stream_output.print_final_summary = should_print_final_summary(continuous, interrupted);
     stream_output.show_running_only_summary_note =
         continuous && interrupted && stream_output.print_final_summary;
-    for (label, stats) in &stats {
+    for target in &setup.targets {
+        let target_stats = stats.get(&target.label).expect(
+            "every prepared target must have a stats collector inserted before the run begins",
+        );
         if multi_target
             && stream_output.print_final_summary
             && stream_output.config.prints_summary()
         {
             writeln!(stream_output.out)?;
-            writeln!(stream_output.out, "target: {label}")?;
+            writeln!(stream_output.out, "target: {}", target.label)?;
         }
-        stream_output.print_summary(stats)?;
+        stream_output.print_summary(target_stats)?;
     }
     stream_output.out.flush()?;
     if let Some(error) = terminal_error {