feat: add post-step to display final claude code config

Added diagnostic step to cat both ~/.claude/config.json and ~/.claude.json
after Claude Code execution completes. This helps verify that config
updates preserve previous values and shows the final state for debugging.

The step runs with if: always() to ensure config is shown even if tests fail.

Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Author: Claude