feat(maintenance): ui/ux audit improvements for BI analyst persona
- read-only access to /maintenance for analysts (sidebar + hidden management)
- hub badge: message tooltip, link to events, accessible aria-label, localized end
- keep hub badge fresh via shared maintenance WS (init on dashboards page)
- events table: message column, auto-end indicator, localized statuses
- confirm dialog before starting maintenance with affected-dashboards summary
- surface load errors inline; localize store toasts
- auto-end discoverability hints in form and table
- form: multiple tables, end>start validation, timezone note
- status colors: active -> warning; completed tab dashboards expandable
- settings: timezone select, fieldset, localized units/aria labels
- backend: expose auto_end in event items, message in banner states
busya
db255ea4e6