ln-73-system-design-proposal-builder

# System Design Proposal Builder **Goal:** Create a proportionate, evidence-backed target system design that turns requirements into explicit boundaries, contracts, data flow, failure behavior, operations, and tradeoffs. Change only the approved design document; do not implement, audit, or approve the delivery. **Execution contract:** Treat the ordered checkbox workflow below as this skill's Definition of Done. Work through every item in order, and mark it complete only when its action and required evidence are complete. `N/A`, skipped, unavailable, or delegated items remain incomplete. Before returning, apply this skill's verdict and approval rules to every incomplete item and prepend **Checklist: X/Y complete**<br>**Incomplete: None | section/item — reason; outcome impact; exact next action**; list every incomplete item. ## Tool Routing | Need | Preferred capability | Fallback | |---|---|---| | Requirements and constraints | Approved requirements, baseline, decisions, and direct stakeholder input | Mark material gaps and ask the smallest decision question | | Current implementation and conventions | Repository search, manifests, entrypoints, and architecture artifacts | Treat as greenfield only when the user or repository establishes that fact; otherwise mark current state `UNKNOWN` and return `REVISE` or `BLOCKED` when the gap can change boundaries, compatibility, or migration | | External capabilities and limits | Current official documentation and specifications | Ma...