Docs sync

Read-only until the user approves a numbered list of changes.

The standard

The developer-os repository keeps copyable versions in templates/project/; the installed plugin does not ship them, so scaffold from this list:

• Root AGENTS.md (under 100 lines): purpose, commands, ## Likely agent mistakes here, stack, non-obvious architecture, conventions, dependency policy, do NOT, ## Invariants, docs map with the sync rule line (behavior change = docs update). CLAUDE.md is one line, @AGENTS.md. _Context.md: a signpost of at most 25 lines with a Vault project slug: line and a dated "State as of".
• Root DESIGN.md for a project with a UI: YAML tokens, then Overview … Do's and Don'ts.
• The backlog (TODO.md and TODO-done.md, or the Backlog: paths) in the audit-to-backlog item format; audit-to-backlog, project-baseline or spec creates it, not this skill.
• .gitignore ignores the state file: git check-ignore -q docs/plans/.devos-state.md exits 0; otherwise list it under Missing. The SessionStart hook shows it only when it is git-ignored. Likewise .worktrees/: git check-ignore -q .worktrees/x exits 0, otherwise list it under Missing; implement-backlog and parallel-lanes run parallel work only then.
• Every tracked doc under docs/ (git ls-files docs; git-ignored files such as plans are exempt) starts with frontmatter status (current, draft, or deprecated), owner, and last-verified (YYYY-MM-DD, the day it was checked against the code).
• docs/index.md: a | Task | Read first | table routing each common task to one doc.
• docs/CURRENT-STATE.md: a Verified at commit: <short sha> line, then ## Works (with entry points as path:line), ## In progress, ## Known broken or missing.
• docs/pitfalls.md: deliberate settings that look like defects; per entry Where, Looks like, Why it is deliberate, Breaks if changed.
• docs/decisions/NNNN-slug.md, numbered from 0001: Date, Status (proposed, accepted, or superseded by NNNN), Context, Decision, Consequences, Alternatives rejected, Revisit when. The template's 0001-template.md is a copy source, not a decision; it is never kept. One decision register with IDs is an accepted alternative. When scaffolding a decision whose reason is in neither the git history nor the docs, write Reason not recorded in Context and list it under open questions; never infer a rationale from the code.
• docs/runbooks/: deploy, rollback, incident procedures.

Propose only pieces that would carry real content now; say which you skip as empty.

1. Inventory

• Find the instruction files (AGENTS.md, CLAUDE.md, _Context.md) and the docs root (docs/, or the one AGENTS.md names). Respect an existing layout that serves the same purpose (one decision register with IDs instead of ADR files, doc/ instead of docs/); do not propose renaming it.
• Read git log --oneline -30 and git rev-parse --short HEAD.

2. Missing pieces

List each piece of the standard that is absent, with the content it would start with. Docs without the three frontmatter keys count as one item, listing the files.

3. Drift

Check claims against the code. Each finding names the doc path:line, the claim, and the evidence that contradicts it:

• Commands in AGENTS.md/CLAUDE.md/README that are not scripts in the package manifest, Makefile, or equivalent, and manifest scripts used in CI that no doc mentions.
• Paths, files, and path:line references in docs that no longer exist (git ls-files, rg).
• Stack versions that differ from the manifest or lockfile.
• docs/CURRENT-STATE.md: its commit is not an ancestor of HEAD (git merge-base --is-ancestor), or more than 50 commits behind; claims under "Works" whose entry point is gone.
• _Context.md "State as of" date older than the last commit touching the code it describes.
• Docs whose last-verified is older than the last change to the code they cite.
• Decision records that contradict each other or the code, or one whose Status is accepted although a later record replaces it. Report these before proposing any broad change, since the change may rest on either side.
• DESIGN.md older than the last change to the styling sources (tailwind.config.*, global stylesheets such as globals.css, theme files): the tokens may no longer match the code.

Report only what you checked; say which probes did not apply.

4. Refresh CURRENT-STATE

Draft the new docs/CURRENT-STATE.md: verify each existing line against the code, drop or move the ones that no longer hold, add shipped work from the commits since the recorded one, set Verified at commit: to HEAD's short SHA and last-verified to today. Show it as a diff.

5. Likely agent mistakes

Propose at most three items for ## Likely agent mistakes here in AGENTS.md, from git history (reverts, "fix"/"revert" commits that undo a change in the same files, files changed repeatedly in fix commits) and from corrections the user made in the current conversation; never open session transcript files. Each item states the mistake, the correct action, and its evidence as commit <short sha> or session <YYYY-MM-DD>. Propose nothing without evidence. Keep AGENTS.md under 100 lines; if the section would push it over, say what to cut.

6. Report and ask

Docs sync — <repo> at <short sha>
Missing: 3   Drift: 5   CURRENT-STATE: 41 commits behind   Mistake candidates: 2

1. [missing] docs/pitfalls.md — two entries: the disabled lint rule in eslint.config.js:12, the retry cap
2. [drift] AGENTS.md:24 says `npm run test:e2e`; package.json has no such script
...
Apply which? A: all (recommended)  B: list numbers  C: none

Stop point

Stop after the report and the question. After approval, apply exactly the approved items, show git diff --stat, and stop; the user commits. When the approved items span more than three docs and none of those docs has uncommitted changes, you may hand them to developer-os:docs-writer instead: the brief holds only the approved items with their path:line and evidence, and this skill's Never rules. Then compare its git diff with the approved items hunk by hunk; list any hunk no item covers in the report and ask whether to keep it. Never discard it yourself.

Never

• Write, create, or delete any file before the user approves the numbered items.
• Overwrite an existing doc wholesale; edit only the approved lines.
• Commit, push, or open a pull request.
• Invent evidence for a mistake item or a drift finding.
• Read session transcripts or files outside the repository.