Plan Architecture

Purpose and inputs

Produce an implementation-structure plan for the user's question. Durable system decomposition and ADRs belong to /f-architecture and ARCHITECTURE.md. Do not mint a second ADR tree.

Steps

1. Load FIRST and read the architecture overlay plus matching technical MDX. If the change is a durable boundary, stop and use /f-architecture.
2. State implementation goals vs nice-to-haves. Stay inside the existing architecture unless the user already authorized a station decision.
3. List constraints, trade-offs, and alternatives that affect this change. Flag high-risk items for a human.
4. Add Mermaid only when structure or flow is otherwise unclear.
5. Save only if the user gave a path; otherwise return in chat. Include assumptions and References. Do not create a branch.

Verification

• The plan does not replace ARCHITECTURE.md or invent an ADR location.
• Assumptions and deferrals are explicit.
• Commands and generated-source owners come from inspected docs.

Handoff

Return the plan location or chat body and whether /f-architecture is still required.