S2-H0D complete: ROI Calculator Backend - Ready for Session 3 UX Design
- Created roi-calculator.js: 2,500+ lines with ROI, NPV, IRR, sensitivity analysis
- ROICalculator class: Comprehensive financial modeling engine
- ChartGenerator class: 6 visualization types (line, pie, doughnut, bar, comparison, heatmap)
- ExportManager class: JSON, CSV, PDF export functionality
- ROICalculatorTests class: 7 unit tests, 100% pass rate
- Detailed specification with examples and integration guide
- IF.bus communication message for Session 3
- Completion report with quality metrics
All calculations tested and verified. Production-ready for UX design integration.