Give the duplication sweep a home, and make it see what it missed

[robertblust]

npm run dupes.

This instrument answers a stated success criterion — "re-running the shingle sweep finds nothing above eight lines that the package does not own" — and it has lived in a scratch directory, been rewritten from memory three times, and been wrong by construction twice. Both errors cost real regressions.

• inventory.mjs only parsed the CHECKS object in verify/check.mjs. So "no check body exists in more than one repository" read as met while 60 lines of suite runner sat outside that object — true of the object, false of the file.
• outside-checks.mjs looked outside CHECKS but still only inside check.mjs, and it anchored on blust.ch and required a run to appear in all three repos. A block shared by only two was invisible. That is exactly how a requestfailed listener and a document.fonts.ready wait — which companygraph and guestgraph had and blust.ch did not — survived a premise scan that concluded the runner was identical everywhere. Consolidating on that premise then removed a working check from the two sites that had it.

This one reads every file and reports two-of-three as loudly as three-of-three.

What it says today:

  in all three :  63 runs, 1339 lines
  in two only  :  81 runs, 1588 lines   <- invisible to both earlier tools
  total        : 144 runs, 2927 lines

More than half the duplication in this family was unmeasurable by the tools that were reporting on it. The largest clusters, which are the honest scope of the remaining consolidation work:

lines	repos	where
540	3/3	the four decks' shared markup — tier 2b, never finished
302	3/3	verify/og-recipe.test.mjs
297	2/3	build/instance.mjs
253	2/3	verify/instance.test.mjs
199	3/3	CLAUDE.md — shared conventions prose
141	3/3	og-check.mjs
80	3/3	og-recipe.mjs

Fence bodies and the package's own whole-file copies are excluded — those are duplicated across repositories on purpose, that being the design.

🤖 Generated with Claude Code