Fixed critical UX issue where npm install would stall and
prompt users to type 'npm fund', blocking installation.

Changes:
- Postinstall script uses /dev/tty for direct terminal output
- Install now completes smoothly without user interaction
- Removed debug code from postinstall script

This fixes the adoption-killing install experience.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>