test: assert pruned count unconditionally in summary test

Remove the conditional guard on pruned trial assertions since the test
explicitly prunes 2 trials. Assert the expected count first, then check
summary content unconditionally to catch regressions.

tests/study/summary.rs

@@ -47,13 +47,11 @@ fn test_summary_with_pruned_trials() {
         study.prune_trial(trial);
     }
 
+    assert_eq!(study.n_pruned_trials(), 2);
     let summary = study.summary();
-    // Should show breakdown when there are pruned trials
-    if study.n_pruned_trials() > 0 {
     assert!(summary.contains("complete"));
     assert!(summary.contains("pruned"));
 }
-}
 
 #[test]
 fn test_display_matches_summary() {