Replace Mock Data with Real System Data on Admin Dashboard Metrics

The Admin Dashboard currently displays mock or hardcoded values for key system metrics, including:

- Active Members

- Active Projects

- Upcoming Events

- Blog Post Counts

These values should be replaced with real data fetched from the appropriate backend endpoints. Each metric must accurately reflect the current state of the system and stay in sync with actual records in the database.

Ensure the following:

- All dashboard metrics consume live API data

- Data is correctly mapped and displayed

- Loading and error states are handled gracefully

- Values update correctly as records change in the system

This will ensure the admin dashboard provides a reliable and accurate overview of platform activity.