feat: enhance stats visualization with improved charts and time range selection

[AndyBold]

Summary

• Fixed chart interpolation to use straight lines between data points instead of curved splines
• Refactored duplicated chart code into reusable components for better maintainability
• Fixed layout recursion warning during chart rendering
• Improved DetailedStatsView performance by optimizing view update strategy
• Added CLAUDE.md with project guidelines and common patterns

Changes

Chart Interpolation

• Removed .interpolationMethod(.catmullRom) from all charts
• Charts now use linear interpolation (straight lines) for accurate data representation
• Applied to: CPU, Memory, Network I/O, and Block I/O charts

Code Refactoring

• Created 4 reusable chart components:
  • CPUChart - configurable with height and showXAxis parameters
  • MemoryChart - configurable with height and showXAxis parameters
  • NetworkIOChart - configurable with height and showXAxis parameters
  • BlockIOChart - specific for detailed view with dual read/write lines
• Eliminated ~200+ lines of duplicated code
• Both main Stats view and DetailedStatsView now use the same chart components

Bug Fixes

• Fixed layout recursion warning by using explicit axis configurations instead of conditional rendering
• Fixed DetailedStatsView performance issue (2+ second pause) by using targeted .id() modifiers on individual sections instead of entire view hierarchy
• Confirmed time range filtering works correctly - charts update based on selected time span

Documentation

• Added CLAUDE.md with project guidelines including:
  • Critical SwiftUI patterns (label wrapping prevention)
  • Thread safety patterns
  • Code conventions
  • Git commit message format

Test Plan

• Charts display with straight lines between data points
• No layout recursion warnings in console
• DetailedStatsView loads quickly without long pause
• Time range selector properly updates charts
• Charts display correctly on both main Stats view and DetailedStatsView

🤖 Generated with Claude Code