feat(tui): implement browser DevTools-style trace viewer with tabbed …

[kunalkushwaha]

…interface

Major UX improvements to the AGK trace TUI:

• Add tabbed interface inspired by Chrome DevTools Network tab

  • 5 tabs: Overview, Prompt, Response, Attributes, Timing
  • Tab navigation with ←→ arrow keys and number keys 1-5
  • Active tab highlighting with visual feedback

• Improve navigation and key bindings

  • Tab switching now works globally (no focus required)
  • Dedicated h/l keys for tree collapse/expand
  • Consistent tab switching in both tree view and detail view

• Implement full-screen layout

  • Remove BoxStyle width constraints
  • Detail viewport now uses full terminal width and height
  • Proper height calculations to prevent content overflow

• Add fixed status bar at bottom

  • Always visible tooltip/help bar
  • Context-sensitive key bindings display
  • Shows current view/focus indicator
  • Displays search match count when active

• Fix viewport scrolling

  • Keep global header fixed at top
  • Only scroll within panels, not entire screen
  • Proper height allocation for panels

This creates a more intuitive and professional trace inspection experience with familiar browser DevTools UX patterns.