Redesign audit center UI with dashboards & quick filters

Comprehensive UI/UX overhaul of Audits.razor:
- Adds summary dashboard cards, quick filter chips, and collapsible advanced filters
- Improves table layout, sorting, and detail view with tabs
- Adds export (CSV/JSON), refresh, and copy-to-clipboard features
- Introduces related events dialog for correlation/trace navigation
- Enhances filtering (Tenant ID, Search), filter state handling, and error feedback
- Refactors styles and helper methods for modern, user-friendly experience

Author: iammukeshm