Refactored Rendering Engine

What: Terminal rendering code reorganized for better maintainability and to support ink2 mode.

Details:

• Split render() into render_v1() and render_v2() methods
• Cleaner separation between legacy and new rendering paths
• Improved parameter passing (prevFrame explicitly passed instead of using instance state)
• Better handling of non-TTY output modes
• Evidence: Class RG1 with split rendering methods at line 67663 in pretty-v2.0.34.js