test(mediabunny): [PKG-MB-09] start hour-scale installed playback checks

refactor/tasks.json

@@ -4021,7 +4021,9 @@
         "baselines/mb-native-pip-checkpoint.json",
         "changes/2026-09-12-PKG-MB-09-sustained-playback-checkpoint.md",
         "baselines/mb-sustained-validation.json",
-        "baselines/mb-sustained-media.json"
+        "baselines/mb-sustained-media.json",
+        "changes/2026-09-16-PKG-MB-09-hour-soak.md",
+        "baselines/mb-hour-soak-start.json"
       ]
     },
     {