[plan] Create workflow cost/ROI calculation template

[github-actions]

Objective

Create a standardized template for calculating workflow costs and ROI to help justify automation adoption.

Context

From discussion #12461: Only 1/8 workflows (DO-1) included ROI calculations, despite high-frequency workflows having measurable cost and time savings. PM and executive stakeholders benefit from cost justification.

Approach

1. Create a new template file: .github/templates/workflow-roi-template.md

2. Include the following sections:

   • Cost per run: GitHub Actions minutes, API calls, external service costs
   • Frequency: Estimated runs per month
   • Time savings: Hours saved per run (manual alternative)
   • ROI calculation: Formula and example
   • Break-even analysis: When automation pays for itself

3. Update developer.instructions to reference this template:

   • Add guidance: "For high-frequency workflows (PR automation, scheduled), suggest cost/ROI analysis"
   • Reference the template file
   • Specify when to include ROI (>10 runs/month, >30min manual time)

Files to Modify

• Create: .github/templates/workflow-roi-template.md
• Update: .github/instructions/developer.instructions.md
  • Add section "Cost and ROI Guidance"
  • Reference the template
  • Specify criteria for including ROI analysis

Acceptance Criteria

• Template includes all 5 sections with examples
• Formula is clear and reusable (cost savings - automation cost) / automation cost
• Developer instructions reference the template
• Guidance specifies when to proactively suggest ROI analysis
• Example calculation matches DO-1 format ($6,000+ savings, 29,900% ROI)

AI generated by Plan Command for discussion #12461