refactor: Redesign calendar and statistics sections and enhance responsiveness
This MR redesigns the Calendar and Statistics sections of the Community Manager agent to follow the new design pattern and improves responsiveness across all screen sizes.
- Redesign calendar container, toolbar, and filters
- Enhance responsive breakpoints for toolbar buttons, navigation, and date display (xs, sm, md, lg)
- Update event content and platforms popover styling
- Redesign all statistics cards and charts
- Enhance responsive breakpoints for all chart components (xs, sm, md, lg, xl)
- Improve chart container sizing with ResizeObserver for dynamic width calculation