GHCP - Run: Ex3 Multi-File Refactor

[DWSPalmer]

Title: GHCP - Run: Ex3 Multi-File Refactor

Summary

• Added shared observability helper module samples/book-app-project/observability.py
• Refactored samples/book-app-project/utils.py and samples/book-app-project/books.py to use shared emit/toggle helpers
• Added run-level refactor notes in ai-track-docs/run-refactor-ex3.md

Evidence

• Validation command:
  • cd samples/book-app-project
  • . .venv/bin/activate
  • python -m pytest tests/test_utils.py tests/test_books.py -q
• Key output:
  • 20 passed in 0.10s

Risk and Rollback

• Risk: low
• Rollback: revert commit fa01ef8

Track

• Level: Run
• Exercise: Ex3