AGENTS.md's dependency-edge list disagrees with cargo metadata on nine crates

[justin13888]

AGENTS.md's "Dependency edges (a crate depends on those to its right)" list is the repository's
own map of the workspace graph, and CLAUDE.md is a symlink to it, so it is the first thing both
a contributor and a tool read. Nine of its edges no longer match cargo metadata.

Measured with:

cargo metadata --no-deps --format-version 1 \
  | jq -r '.packages[] | "\(.name): \([.dependencies[]
      | select((.kind//"normal")=="normal" or (.kind//"normal")=="build") | .name] | join(", "))"' \
  | sort

Crate	AGENTS.md says	cargo metadata says	Gap
gamut-deflate	← core	(nothing)	claims an edge that does not exist. crates/gamut-deflate/src/lib.rs:6 — "with no internal dependencies of its own"; the manifest has no [dependencies] table at all
gamut-dsp	← core (shared with the gamut-color / gamut-bitstream line)	(nothing)	claims an edge that does not exist. The line is right for gamut-color and gamut-bitstream and wrong for gamut-dsp
gamut-isobmff	← core, bitstream	← core	claims gamut-bitstream, which it does not use
gamut-riff	← core, bitstream	← core	same line, same gap
gamut-jpeg	← core, color, dsp	← codec-abi, color, core, dsp	missing gamut-codec-abi
gamut-heic	← isobmff, core, color	← codec-abi, color, core, isobmff	missing gamut-codec-abi
gamut-png	← core, deflate (+ miniz_oxide)	← codec-abi, core, deflate, miniz_oxide	missing gamut-codec-abi
gamut-webp	← avif's list + riff (so: av1, isobmff, core, color, codec-abi, riff)	← codec-abi, color, core, dsp, riff	claims gamut-av1 and gamut-isobmff, which it does not use; missing gamut-dsp
gamut-tiff	← ifd, core, bitstream	← bitstream, core, deflate, ifd, miniz_oxide	missing gamut-deflate and miniz_oxide
gamut-dng	← ifd, bitstream, color, metadata, core (+ miniz_oxide)	← bitstream, color, core, deflate, ifd, jxl, metadata, miniz_oxide	missing gamut-deflate and gamut-jxl

Three of these matter beyond tidiness:

1. gamut-codec-abi is missing from three consumers' edges (gamut-jpeg, gamut-heic,
   gamut-png) in the same document that describes the codec-abi seam as the one door a backend
   enters by. A reader reconstructing the seam's reach from the edge list gets three crates fewer
   than there are.
2. gamut-dng ← gamut-jxl is an undocumented edge between two format crates, and it is not
   an obvious one from either crate's description.
3. The two "← nothing" crates are not the ones the document names. It says gamut-codec-abi
   is "dependency-free (not even on gamut-core)" — true — while gamut-deflate and gamut-dsp
   are equally dependency-free and are both listed as ← core.

Suggested fix

Re-derive the whole edge list from cargo metadata once, and consider a mise task that
compares the list against the graph, in the shape of check-readme-crates
(tooling/check-readme-crates/run.sh) — the same failure mode (a hand-maintained summary of the
workspace that nothing read) and the same remedy.

Why filed rather than fixed

Found while correcting the README crates table (#425, PR #526) — the gamut-deflate row now
states that the crate has no runtime dependency of its own, which AGENTS.md contradicted. That
one line is corrected in PR #526 because the PR's own diff would otherwise contradict it; the
other eight edges are a separate audit of a different document section, and widening a
documentation PR past its stated boundary is what the PR exists to argue against.

Related

• STATUS.md drift: gamut-dsp lists a shipped module as deferred, gamut-avif contradicts itself #545, gamut-av1 and gamut-avif publish crate descriptions that their own source contradicts #560, Crate doc summary lines that their own source contradicts: gamut-color "pixel formats", gamut-cli's decode path #590 — the same class one level down: a per-crate summary line its own source
  contradicts.
• README: crates table misdescribes six shipped crates and omits gamut-dng #425 / PR docs(readme): correct the crates table against each crate STATUS.md, and gate it #526 — the README crates table, and the guard that now gates its membership.