Fix/tests

[OwnerOfJK]

Fix test suite and modernize example apps

This PR comprehensively updates and fixes the test suite for all PixeLAW example apps while
modernizing them to use the latest framework versions (Dojo 1.5.1, PixeLAW 0.7.8, Cairo
2.10.1).

Key Changes:

• Fixed broken tests across all example apps (chest, hunter, maze, minesweeper, pix2048, rps,
  tictactoe)
• Modernized app structure to follow current PixeLAW patterns and Dojo ECS conventions
• Updated dependencies to latest stable versions with proper external contract configurations
• Added comprehensive documentation including app creation guide and PixeLAW developer agent
• Improved CI/CD with automated formatting checks and test validation
• Enhanced DevContainer setup for streamlined development experience

Apps Updated:

• Refactored and fixed tests for chest, hunter, maze, minesweeper, pix2048, rps, and tictactoe
• Removed deprecated brc2048 app
• Added proper error handling and Cairo 2.x syntax compliance

This ensures all example apps serve as reliable references for PixeLAW development and
maintain compatibility with the latest framework versions.