Terminal diagrams

1. Contract and semantic graph

1. RECORD architecture/schema/topology/process/dependency/state/table/repair scope, target (markdown_code_block | ansi_terminal), charset, max columns, width policy, alignment/flow/hierarchy/emphasis, and rectangular component boundaries.
2. STRUCTURED request -> COPY assets/layout-request.json; validate against assets/layout-request.schema.json.
3. LIST stable node IDs, labels/body/border/style and edge direction/label/route. Collapse only decorative distinctions.
4. ORDER by reading flow/dependencies; top-down for long sequences, left-right for compact pipelines. Label return edges for cycles; placement/color alone cannot imply direction.
5. CHOOSE Mermaid/SVG if browser scaling/exact graph routing is required instead of terminal text.

Gate: each box/edge maps to semantics; no orphan or ambiguous direction.

2. Width

READ references/width-model.md for non-ASCII or ANSI.