refactor: consolidate Discord command handlers into bot.js

  - Moved ping, tracker, and roll command functionality from separate files into source/bot.js
  - Organized code with clear section headers for definitions, execution, and handlers
  - Improved maintainability by centralizing all command logic in a single file
  - Removed source/InteractionCreate.Commands/ directory and individual command files
  - Maintained identical functionality while enhancing code structure and readability

Author: zuedev