- Implement GetTenantDashboard with usage stats, metrics, recent events, and quota status
- Implement GetUsageAnalytics with usage by type, trends, and peaks
- Implement GetPerformanceAnalytics with API performance, resource performance, errors, and slow queries
- Extract helper methods to tenant_analytics_mock.go: parseTimeRange, parseAPIRequestEvent, parseErrorEvent, parseSlowQueryEvent, calculateAPIPerformance, build