DIALECT-09: Require an anchor with a contract

What it demonstrates

A declared section anchor emits structure/anchor-missing when no matching ^id resolves.

Builds on: DIALECT-02: Anchor a section, read it from .anchors

How it’s done

Commands, code, and output together; comments mark which is which.

summary.contract.yaml

mcVersion: 1
kind: contract
body:
  sections:
    - section: Summary
      anchor: summary      # a ^summary must resolve in this section

$ markdown-contract validate --contract summary.contract.yaml --path notes
# error  structure/anchor-missing  section 'Summary' is missing required block-id ^summary

Surfaces exercised

• declarative contract section.anchor
• structure/anchor-missing rule
• validate CLI --contract/--path