fix: align SOBC command with HM Treasury Green Book 2026

[tractorjuice]

Summary

• Autoresearch-optimised the /arckit:sobc command prompt over 5 iterations, improving output quality from 8.0 → 9.4 (18% improvement)
• Aligned with the actual HM Treasury Green Book (2026) by adding missing requirements and correcting options terminology
• Companion to fix: align risk command with UK Gov Orange Book 2023 #216 (risk/Orange Book alignment) — together these align the two core UK Gov framework commands

Changes

Change	Before	After
Strategic Case	Problem + drivers + scope	+ Theory of Change (inputs→outcomes→impact) + SMART spending objectives
Options naming	"Do Nothing, Minimal, Balanced, Comprehensive"	Green Book 2026: "BAU, Do Minimum, Preferred Way Forward, More Ambitious, Less Ambitious"
Options appraisal	Simple pros/cons	+ Critical Success Factors as filter criteria
Economic analysis	NPV/ROI only	+ Appraisal Summary Table (AST) + Value for Money balanced judgment (6 factors)
Business case context	No lifecycle context	ROAMEF cycle (Rationale→Objectives→Appraisal→Monitoring→Evaluation→Feedback)
Five Case Model	Described sequentially	Explicitly iterative per Green Book 2026
SOBC/OBC/FBC stages	Basic descriptions	Green Book 2026 aligned (longlist→shortlist→procurement review)

Autoresearch Results

iter 0: 8.0 baseline                                              KEEP
iter 1: 9.0 Theory of Change + SMART + options terminology + ROAMEF KEEP
iter 2: 9.0 AST + VFM (options naming regressed)                  DISCARD
iter 3: 9.4 AST + VFM + enforced Green Book option names          KEEP
iter 4: 9.6 distributional analysis + switching values (delta 0.2) DISCARD

3 keeps, 2 discards across 5 iterations. Converter run included — all 7 distribution formats updated.

Test plan

• Run /arckit:sobc 001 in a test repo with STKE artifact
• Verify Theory of Change section present in Strategic Case
• Verify SMART spending objectives with IDs (SO-xxx)
• Verify options use Green Book 2026 names (BAU, Do Minimum, Preferred Way Forward, etc.)
• Verify Critical Success Factors section present
• Verify Appraisal Summary Table (AST) present
• Verify Value for Money judgment references all 6 Green Book 2026 factors

🤖 Generated with Claude Code

[tractorjuice]

Superseded by #265 (autoresearch includes deeper optimisation of this command)