sync-upstream

Reconcile the forked skills with a new upstream release: disposition every upstream delta, gate every disposition on the user's approval, audit the whole divergence surface, and record the new sync point. Nothing enters the repository without an approval, and a case these rules do not cover is put to the user rather than improvised on.

Step 1: Measure

Get the exact new tag from gh release list -R <upstream>. Every measurement comes from scripts/fork-diff.sh (through mise run dev:fork-diff -- …); fetch nothing by hand. The tool reads each fork's source: frontmatter, re-prefixes its bare pinned version into the real tag, resolves the upstream skill's directory from the repository tree API rather than guessing it, fetches and caches the upstream files under .scratch/sync/, and prints a unified diff per file with a divergent-line count.

Run it twice:

• With no skill arguments, against the pins: every fork measured, whether or not upstream moved it. This is the audit — a release touching three files still gets all the forks measured, drift nobody has looked at being the audit's whole point.
• With --tag <new-tag> and the updated upstream's forks named, since one tag cannot be right for both upstreams. Pass the tag exactly as the release lists it, prefix included: the tool uses the override verbatim, re-prefixing only the pinned source: version. A wrong tag prints skipped: could not read the tree per fork and exits zero: an all-skipped second run is a failed measurement, never zero deltas. Check each fork's tag line, printed under its ════ header as <repo>@<version> → <tag>, upstream skill '<name>': a tag line still naming the pinned tag means the override named the pin, not the release — the same failure — while identical hunks under the new tag are a real zero-delta release, not a failure. A fork with no tag line was skipped, never measured.

First set aside what was not measured: a file or fork the run could not read — could not fetch, upstream copy unreadable, a skipped fork, or an upstream only line carrying (size unknown, fetch failed) — classifies as nothing, whatever else its label says. Retry unread files once with --refresh; park what a second attempt still cannot read, since an absent measurement is never a delta and never convergence. Parking is per measurement: a fork skipped at the new tag keeps its pin-run measurement, whose hunks stay audit material. For the updated upstream's forks, classify each remaining spot by whether upstream moved there, read from the upstream side of the two runs' diffs — hunk headers and context shift with unrelated edits, so compare the quoted upstream lines, never the hunk framing. Where the upstream side reads the same in both runs, upstream left that text alone: the fork's divergence there is pre-existing — audit material. Where the upstream sides differ, or a hunk shows in only one run, upstream moved: an upstream delta for Step 2, whose Standing-or-afresh question Step 2's anchoring rule decides. A file the tool reports whole takes the same both-runs test: the same report in both runs is pre-existing — a never-ported or fork-only file, audit material — while a report in one run alone, pin or new tag, means upstream moved that file: an upstream delta. Upstream edits inside a file the fork never carried are invisible to these diffs; where a ledgered policy asks for their evaluation — the preamble's persona rule — diff the two cached tags under .scratch/sync/. The non-updated upstream's forks are measured once, against their pins, so every hunk they show is audit material. Treat source: as provenance, not ground truth: a fork may have been cut from upstream main between releases and already contain wording "newer" than its recorded version. An audit divergence is therefore not proof of local invention: a revert proposal states the divergence and leaves its origin open — for the non-updated upstream the run holds nothing newer than the pin, so origin stays uncheckable until that upstream's own sync.