Draw an interactive trendline chart using Chart.js with custom tooltips, plotting visitor statistics over time.
Create a line chart with time-based data. Each point shows a value, and hovering reveals a custom tooltip.
Configure the Chart.js line chart with labels (e.g., months) and datasets. Customize the tooltip callbacks to show formatted values.
Style the line, points, and grid for a clean look.
Test that hovering shows tooltips and the trendline renders correctly.
