The DisableDockerUpdateActions setting was being saved to disk but not updated in h.config, causing the UI toggle to appear to revert on page refresh since the API returned the stale runtime value. Related to #1023
Cover legacy JSON format migration and current format with nil/expired entries. Improves load function coverage from 67.9% to 100%.
Cover saveUnsafe (57.9% to 89.5%) and load (50.0% to 67.9%) error paths
