fix: Deploy enhanced GitHub issue creation workflow to master (#240)

- Implements structured JSON output approach instead of complex gh commands
- Adds robust fallback mechanism for pending issue creation
- Includes pre/post-discovery verification steps
- Enhances error handling and logging throughout workflow
- Replaces 340+ line complex prompt with focused, actionable instructions

Resolves issue where Claude Code couldn't execute complex gh issue create commands,
causing workflow to complete successfully but create no GitHub issues.

Tested manually with successful creation of 5 AWS Backup feature issues (#235-#239).

Author: lgallard