// Minimal stand-in for the real `cph-render` package, used so cph-typst's
// World / compile / PDF path can be proven independently of WU-2.
//
// It exercises the same call shape as the real entry: it reads `info`, walks
// `parts` IN ORDER, and renders each part's content fields by `kind`. Content
// values are already-evaluated content (the driver produced them via include).
#let display(info: (:), target: "student", parts: ()) = {
  set document(title: info.at("title", default: ""))
  [= #info.at("title", default: "")]
  [target: #target]
  for p in parts {
    let kind = p.at("kind", default: none)
    [== #kind]
    if kind == "segment" {
      p.textbook
    } else if kind == "lemma" {
      p.stmt
      let proof = p.at("proof", default: none)
      if proof != none { proof }
    } else if kind == "example" {
      p.problem
      p.solution
      let src = p.at("source", default: none)
      if src != none [来源：#src]
    } else if kind == "sop" {
      p.sop
    }
  }
}