feat: implement zoom and scroll controls for timeline view

[renjfk]

Add interactive zoom and scroll functionality to the timeline view for better navigation and detailed analysis of work patterns throughout the day.

Details

• Add horizontal scroll control at the bottom of HourlyTimelineChart with zoom handles on both sides
• Enable drag-to-zoom functionality on handles to adjust visible time range with smooth continuous zooming
• Set maximum zoom level to 1-hour detailed view to maintain usability and performance
• Add drag-to-scroll functionality on middle area of control bar to pan across timeline
• Provide smooth animations for zoom and scroll transitions using SwiftUI animations
• Update time labels dynamically to reflect current visible time range based on zoom level
• Maintain accurate positioning and scaling of work period rectangles during zoom operations
• Preserve zoom state when switching between dates or view modes
• Add visual indicators showing current position within overall timeline
• Support trackpad gestures for natural macOS interaction patterns
• Reset to full day view when switching to different dates

This enhances timeline usability for detailed analysis of work patterns and break periods.