[d-morrison]

Requested by Ezra · project thread

Part of Morrison-Lab/ai-config#5408.

Why

Resolving a merge conflict by keeping one side of a whole file has silently dropped definitions, citations and code from the notes before.
gha's check-merge-drops (Morrison-Lab/gha#958) flags a merge commit whose tree lacks lines either parent added since the merge base, but on 2026-11-12 none of the notes repos (lds, mds, pds, sds, mcs, psw, psc) called it.

What changes

One new file, .github/workflows/check-merge-drops.yml: the consumer from gha's examples/check-merge-drops.yml, pinned at @v3, with two changes:

• fail: true, so a merge that drops content fails CI instead of only writing a warning to the job summary.
• permissions: contents: read on the calling job, which is what the reusable workflow requests and what check-caller-permissions expects.

On a pull request it checks only the merges the PR adds (such as a merge of main into the branch); on a push to main, the merges the push brought in.
A PR with no merge commits passes trivially.

Expected effect

A dry run of the checker (default globs, min-length and similarity) over the last 300 commits on lds main (281 merges) flagged 3 merges, each dropping one line.
At least one was deliberate: a bullet removed on a branch that converted bullets to prose.
So with fail: true, a deliberate drop will fail this check about once in a hundred merges, and needs a "merge anyway" from Ezra.

Making it a required status check is a branch-ruleset setting, which this PR does not change.

Not done

• Merging this changes a workflow file on main, which marks the repo's other open PRs stale for the runner's checker; merge it after the content PRs in the queue.

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Generated by Claude Code

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Claude finished review — View run

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I fetched PR #164 live just now. It is open, not a draft, and not merged, and its head is still 93726044cc2145f9d09da38c5fb052cdb84aa42b, the commit I reviewed. The review stands.

Verdict

Ready for merge

Structured Review Data (JSON)

{
  "schema_version": "1.1",
  "reviewer": "claude",
  "commit_sha": "93726044cc2145f9d09da38c5fb052cdb84aa42b",
  "verdict": "CLEAN",
  "findings": [],
  "detailed_assessment": "The new check-merge-drops.yml caller matches the gha example, uses the existing fail input, and pins @v3 like sibling workflows.",
  "holistic_assessment": "A single-file CI addition with explicit read-only permissions and no content, math, or dependency changes, so regression risk is minimal."
}

Reviewed commit: 9372604

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💰 Cost: $0.2088 (review) — run

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PR Preview Action v1.8.2
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_{Built to branch gh-pages at 2026-11-12 12:15 UTC.}