Rebase pushes with the machine-user PAT (action-translation#125) (#187)

* Rebase pushes with the machine-user PAT (action-translation#125)

Commits pushed with the default GITHUB_TOKEN trigger no workflows, so a
rebased branch gets a run-less head: force-pushed re-translated content
lands unreviewed, and with required checks a run-less head blocks
merging. Measured both ways on the test harness 2026-07-21 — zero runs
under GITHUB_TOKEN, review triggered under the PAT.

Sync mode has always passed the PAT for exactly this reason; rebase
pushing to the same PRs with a weaker token was an inconsistency, not a
decision.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Rebase: require a same-repo head branch (fork noise guard)

Fork PRs never receive secrets, so the PAT is not exposed — but a
merged fork PR whose branch matched a translation prefix would start
the job with an empty token and fail red. Skip it instead. Mirrors
action-translation#130.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: mmcky

.github/workflows/rebase-translations.yml

@@ -25,8 +25,13 @@ jobs:
     # Keep this in step with `isTranslationBranch` in the action's src/branch-naming.ts
     # — this `if` decides whether the job runs, that predicate decides which open PRs
     # it then rebases, so a prefix matching only one of them is a no-op run.
+    # The head-repo check is belt-and-braces: fork PRs never receive secrets, so
+    # the PAT is not exposed either way — but a merged fork PR whose branch happens
+    # to match a prefix would otherwise start this job with an empty token and fail
+    # red. Same-repo branches matching these prefixes only come from the tooling.
     if: >
       github.event.pull_request.merged == true &&
+      github.event.pull_request.head.repo.full_name == github.repository &&
       (startsWith(github.event.pull_request.head.ref, 'translation-sync-') ||
        startsWith(github.event.pull_request.head.ref, 'resync/'))
     runs-on: ubuntu-latest
@@ -46,4 +51,11 @@ jobs:
         with:
           mode: rebase
           anthropic-api-key: ${{ secrets.ANTHROPIC_API_KEY }}
-          github-token: ${{ secrets.GITHUB_TOKEN }}
+          # PAT rather than the default GITHUB_TOKEN, deliberately: commits pushed
+          # with GITHUB_TOKEN trigger no workflows (GitHub's recursion guard), so a
+          # rebased branch ends up with a run-less head — force-pushed re-translated
+          # content lands unreviewed, and with required checks a run-less head blocks
+          # merging. Validated both ways on the test harness, 2026-07-21: zero runs
+          # under GITHUB_TOKEN, review triggered under the PAT.
+          # See QuantEcon/action-translation#125.
+          github-token: ${{ secrets.QUANTECON_SERVICES_PAT }}