Diagnostics and strict mode

Typst has no public API for a script to emit its own compiler warning, so every check below shows instead as a visible box, right at the fault — muted for anything embedded in the manuscript itself when the compile is both variant: "clean" and not preview: true (manuscript.pdf must never carry one, since it’s the file actually sent out under review), shown regardless of mode for anything embedded in the letter (the letter is never sent out for blind review the way the manuscript is, so hiding it in one mode buys nothing). This muting logic itself lives in @preview/contexture, shared with every other package built on it — see Wiring a real project below.

Two already appeared earlier, in context: a numbered anchor with no matching exchange and a bare anchor’s exemption from it; pinpoint with no matching anchor (on-empty:). Four more:

#import "../../lib.typ": *

#set page(width: 16.6cm, height: auto, margin: 12pt)
#set text(size: 10.5pt)
#set-revisions(require-exchange: false)

*Comment with no matching passage anywhere:*
#reviewer(1)[
  #exchange(<r9-1>)[A comment with nothing in the manuscript to answer.][A response anyway.]
]

*Exchange with a blank response:*
#passage(<r9-2>)[#add[A real addition, matched below.]]
#reviewer(1)[
  #exchange(<r9-2>)[A real comment.][]
]

*A mark outside any passage:*
#add[Added text with no enclosing `passage`.]

*A passage with no mark and no `summary:`:*
#passage(<r9-3>)[Plain text, nothing added, removed, or replaced.]

Four more exist but aren’t demonstrated live here, since each needs a slightly unusual setup to trigger: two numbered exchanges sharing one anchor (duplicate exchange r1-2); xref/xcomment pointing at a label or anchor that doesn’t exist anywhere (xref(<fig-x>): not found, xcomment(<r9-9>): no exchange found for this anchor); and an excerpt whose passage contains a label also referenced elsewhere in the bundle, which falls back to citing the page instead of crashing the compile outright — rare in practice, since pinpoint(excerpt: true) already strips labels from what it re-emits before this check would even trigger.

contexture.bundle(strict: true, ...) — the bundle’s own strict: parameter, see Wiring a real project below — turns every one of these into a hard compile error, in both modes, for palimpsest and any other package sharing the same bundle (checkitoff’s checklist diagnostics included, if one is listed too):

#show: contexture.bundle.with(strict: true, ...)

Not the default, since a manuscript mid-revision should still compile — meant for a CI gate right before submission, when every one of these should already be resolved.