Frontend stability fixes

- Preserve loaded content while pages refresh in the background across dashboard, databases, logging, notifications, status page, administration, audit log, and Docker views.
- Smooth tab switching by preloading accessible tab data without replaying full-page loading states.
- Fix stale-cache edge cases around permission changes, filters, pinned proxy cards, Docker tab prefetching, and partial cached datasets.
- Fix live update and tab routing regressions in settings, notifications, monitoring, Docker settings, and related detail views.