Operating procedure for spec-driven development (SDD) with AI coding agents: treat code as disposable and the specification as the durable, versioned asset, then run the Constitution → Specify → Plan → Tasks → Implement loop (GitHub Spec Kit) with behavior-driven Gherkin-style specs. Trigger whenever building software meant to outlive a prototype — production features, multi-session or multi-agent work on one codebase, or legacy regeneration/migration — instead of vibe-coding straight to code.
