[test] add tests for progress manager modes; verify bar counts and total bar visibility in single and multi modes

tests/progress_mode_counts.rs

@@ -0,0 +1,22 @@
+use polyscribe::progress::ProgressManager;
+
+#[test]
+fn test_single_mode_has_no_total_bar_and_three_bars() {
+    // Use hidden backend suitable for tests
+    let pm = ProgressManager::new_for_tests_single_hidden();
+    // No total bar should be present
+    assert!(pm.total_state_for_tests().is_none(), "single mode must not expose a total bar");
+    // Bar count: header + info + current
+    assert_eq!(pm.testing_bar_count(), 3);
+}
+
+#[test]
+fn test_multi_mode_has_total_bar_and_four_bars() {
+    let pm = ProgressManager::new_for_tests_multi_hidden(2);
+    // Total bar should exist with the provided length
+    let (pos, len) = pm.total_state_for_tests().expect("multi mode should expose total bar");
+    assert_eq!(pos, 0);
+    assert_eq!(len, 2);
+    // Bar count: header + info + current + total
+    assert_eq!(pm.testing_bar_count(), 4);
+}