Refactor pod readiness polling to reuse wait_for_pod_ready

[HacksonClark]

In orchestrator/problems/misconfig_app/misconfig_app_hotel_res.py the code now manually polls pod/container status (e.g., the new for _ in range(12): loop). Per the PR discussion, there’s already a helper wait_for_pod_ready in kubectl.py. We should use that instead.

See discussion: #39 (comment)