🎨 Enhanced TUI with professional ASCII art and visual design

Major improvements to the Terminal User Interface:

Visual Enhancements:
• Beautiful DataPilot ASCII art logo in welcome screen
• Professional section headers with box drawing characters
• Enhanced main menu with visual hierarchy
• Improved goodbye animation with farewell message
• Consistent color schemes across all interface elements

Navigation Improvements:
• Added Learning Mode placeholder (📚 tutorials coming soon)
• Added Settings & Preferences placeholder (⚙️ customization)
• Enhanced menu choices with emoji hints and descriptions
• Better visual separation between sections
• Professional boxed layouts for information display

Code Quality:
• Maintained separation of UI logic (engine) and rendering (interface)
• Added new menu handlers for learning and settings modes
• Enhanced color gradients and consistent styling throughout
• TUI unit tests passing (14 engine + 18 flow tests)

User Experience:
• More engaging and professional appearance
• Clear visual hierarchy and navigation cues
• Animated loading effects and progress indicators
• Consistent branding with airplane/pilot theme

Updated Documentation:
• Comprehensive README.md with detailed explanations
• Single executable installation instructions
• Enhanced package.json keywords and description
• Professional project positioning and feature highlights

🤖 Generated with Claude Code (https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: Mrassimo