Fix shakapacker.yml compile setting for development

The compile: false was incorrectly nested under the integrity section
instead of being in production. Added compile: true to development section
to prevent the "Slow setup for development" warning.

This fixes the issue where Rails was compiling assets on-demand during
requests even though bin/shakapacker-dev-server was running.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: justin808