Unit 7: Reusable translation workflow

[mairas]

Target repo: halos-org/shared-workflows

Goal: One caller stanza gives a translated docs repo the report, the comment,
the site build, the anchor check and the gate.

Requirements: R12, R13

Dependencies: Unit 6

Files:

• Create: .github/workflows/translation-status.yml
• Create: examples/translation-status-caller.yml
• Modify: README.md

Approach:

• workflow_call, with a header comment stating caller requirements, matching
  pr-checks.yml.
• Checkout uses full history: the report resolves the stamped blob to show the
  English diff, and a shallow clone silently degrades that to a hint.
• Step order is the design, not an accident: report to the job summary, post or
  patch the comment, build the site, check anchors, then apply the gate. A gate
  that aborts the job earlier would suppress the comment that explains why it is
  red.
• A failed comment post must not fail the job. A pull request from a fork gets a
  read-only token, and a docs contributor should get a review, not a broken
  build.
• Inputs to expose: runner, and the paths that trigger it are the caller's
  concern. Do not add a "translations off" input — a repo without i18n consumes
  the package directly instead (see Key Technical Decisions).
• hatlabs/shared-workflows is not touched.

Patterns to follow:

• .github/workflows/pr-checks.yml for the workflow_call shape and header
• examples/ for the caller stanza convention

Test scenarios:

• Test expectation: none — reusable workflows are not unit-testable here.
  Verification is by observed runs in Unit 8 and Unit 9.

Verification:

• A deliberately stale branch in a scratch repo produces: a comment naming the
  stale pages, a job summary with the full report, and a red check.
• The same branch with the comment step forced to fail still fails only on the
  gate, and the run reaches the gate step.

[mairas]

Merged as halos-org/shared-workflows#39 (88332af on main).

Shipped .github/workflows/translation-status.yml, the caller stanza in examples/docs-repo/, and a README section. Verified by observed Actions runs on a throwaway branch rather than by inspection: all-current green; broken anchor alone red via the re-raise step; stale translation patches the PR comment in place with the English diff and then fails the gate; a caller granting only contents: read gets HTTP 403 on the comment, tolerates it, and still fails the job.

Follow-ups from review, all filed: halos-org/shared-workflows#40, halos-org/shared-workflows#41, halos-org/shared-workflows#43, halos-org/shared-workflows#44.