WIP - Add admin dashboard summary and top-category UI

[OSPFNeighbour]

This pull request introduces a comprehensive dashboard summary for locations, providing an at-a-glance overview of member activity, engagement, and kiosk status over recent periods. It adds new GraphQL types and resolvers to supply this data and implements a new admin dashboard UI to visualize the metrics and trends.

API and GraphQL enhancements:

• Added new GraphQL types (DashboardCategoryPeriodSummary, DashboardDailyPeriodSummary, LocationDashboardSummary) and a dashboardSummary field to the Location type, exposing summary statistics and trends for use in the admin dashboard. [1] [2]
• Implemented the backend logic in Rust to compute and aggregate dashboard metrics (e.g., active members, check-ins, kiosk status, activity durations, daily and category breakdowns) for the past 7 and 30 days, including efficient bucketing and sorting. [1] [2]
• Introduced constants for time windows (e.g., 7 days, 30 days, 24 hours) and session online status to support the dashboard calculations.

Admin dashboard UI:

• Built a new dashboard interface in AdminHome.tsx that queries and displays the summary data, including member engagement stats, kiosk status, activity trends by day and by category, and quick insights. The UI includes bar charts, summary cards, and formatted metrics for clarity.
• Added helper functions for formatting dates, durations, and percentages to improve the readability of dashboard statistics.