Add new utils.sh module with cross-platform support and reliability improvements:
- M1: execute_with_retry() with exponential backoff for transient failures
- M2: validate_yq() to detect Go vs Python yq versions with fallback
- M3: check_phase_completion_fuzzy() for case-insensitive signal detection
- M4: sed_inplace() for cross-platform sed (macOS/Linux compatibility)
- M5: check_branch_protection() to prevent commits to main/master
Update json-output.sh with enhanced JSON extraction using awk for multi-block
handling, normalized status comparison, and fuzzy matching fallback.
Update epic-execute.sh to source utils.sh and use cross-platform sed functions.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Caleb