Create GitHub Issues for unimplemented requirements from specification files using feature_request.yml template

# Create GitHub Issues for Unmet Specification Requirements

Create GitHub Issues for unimplemented requirements in the specification at `${file}`.

## Process

1. Analyze specification file to extract all requirements
2. Check codebase implementation status for each requirement
3. Search existing issues using `search_issues` to avoid duplicates
4. Create new issue per unimplemented requirement using `create_issue`
5. Use `feature_request.yml` template (fallback to default)

## Requirements

- One issue per unimplemented requirement from specification
- Clear requirement ID and description mapping
- Include implementation guidance and acceptance criteria
- Verify against existing issues before creation

## Issue Content

- Title: Requirement ID and brief description
- Description: Detailed requirement, implementation method, and context
- Labels: feature, enhancement (as appropriate)