Summary

Enhance pull-request.prompt.md to automatically discover repository PR templates and merge generated content into the template structure.

Problem

The current PR generation prompt creates a standalone pr.md file that doesn't integrate with repository PR templates. Users must manually copy content into the template sections.

Proposed Solution

Implement Option B (Two-Phase Generation):

1. Step 1.5: Discover PR template at GitHub-standard locations
2. Step 3.5: Merge generated content into template sections with:
   • Auto-checked Type of Change boxes based on file patterns
   • Related Issues populated from commit/branch analysis
   • Security Considerations from security analysis

Acceptance Criteria

• Template discovery works for .github/PULL_REQUEST_TEMPLATE.md
• Fallback to standalone format when no template found
• Change types auto-detected from file patterns
• Issue references extracted from commits and branch names
• Template structure preserved in output

Research

See .copilot-tracking/research/20251212-pull-request-template-integration-research.md