Refresh the catalogues on a schedule, and republish when they change

Mondays 05:23 UTC: re-run the ETL cold against the live archives, and if the
output differs by a byte, gate it on the unit suite and a production build,
commit it to main, and dispatch the Pages deploy. If nothing changed, say so
in the run summary and touch nothing.

The gates run inside this workflow because they cannot run after it: a push
made with GITHUB_TOKEN fires no push workflows at all — GitHub's recursion
guard — so an unguarded push would deploy nothing and be checked by nothing.
The same guard is why the deploy and a visible CI record are dispatched
explicitly afterwards; dispatch events do go through where push events do
not. ci.yml gains a workflow_dispatch trigger for exactly that call.

Also corrects pages.yml's claim that configure-pages enables Pages on first
run. It cannot: the action's `enablement` input requires an admin-scoped
token, which GITHUB_TOKEN is not. If the site has never been enabled, the
first deploy fails at that step and the one-time fix is Settings → Pages →
Source: GitHub Actions.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WaySiNst4HhDXBHnMy8p5G

.github/workflows/data-refresh.yml

@@ -0,0 +1,89 @@
+name: Refresh the catalogues
+
+# Re-runs the ETL against the live archives on a schedule and republishes the site when the data
+# actually changed, so the catalogues track NASA without anyone touching the code. The archives
+# this reads — HYG, the Exoplanet Archive, JPL Horizons, OpenNGC, Gaia — are all anonymous
+# public endpoints; no keys are involved.
+on:
+  schedule:
+    # Mondays 05:23 UTC. An arbitrary minute rather than :00, which is the busiest minute on
+    # GitHub's cron fleet and the most likely to be delayed or dropped.
+    - cron: '23 5 * * 1'
+  workflow_dispatch:
+
+# Never two refreshes at once, and never cancel one mid-push.
+concurrency:
+  group: data-refresh
+  cancel-in-progress: false
+
+permissions:
+  contents: write # push the regenerated catalogues to main
+  actions: write # dispatch the deploy and CI afterwards — see the final step
+
+jobs:
+  refresh:
+    name: Fetch, gate, publish
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    steps:
+      - uses: actions/checkout@v5
+        with:
+          # The data lives on main and the push below goes to main, whichever ref the workflow
+          # file itself ran from.
+          ref: main
+
+      - uses: actions/setup-node@v5
+        with:
+          node-version: 22
+          cache: npm
+
+      - run: npm ci
+
+      # The ETL's cache directory is gitignored and this is a fresh runner, so every source is
+      # fetched live (~50-100 MB). A failed fetch fails the run by design — no refresh is
+      # better than a partial one — except Gaia, which the ETL itself treats as best-effort.
+      - name: Rebuild the datasets
+        run: npm run etl
+
+      - name: Detect a real change
+        id: diff
+        run: |
+          if git diff --quiet -- src/assets/data; then
+            echo "changed=false" >> "$GITHUB_OUTPUT"
+            echo "The archives published nothing new — catalogues are byte-identical." >> "$GITHUB_STEP_SUMMARY"
+          else
+            echo "changed=true" >> "$GITHUB_OUTPUT"
+            { echo "Catalogue changes:"; echo '```'; git diff --stat -- src/assets/data; echo '```'; } >> "$GITHUB_STEP_SUMMARY"
+          fi
+
+      # The same gates CI runs, run here instead: the push below is made with GITHUB_TOKEN, and
+      # GitHub deliberately fires no workflows for such pushes, so the data must be proven
+      # before it lands rather than checked after.
+      - name: Unit tests against the new data
+        if: steps.diff.outputs.changed == 'true'
+        run: npm test -- --no-watch
+
+      - name: Production build against the new data
+        if: steps.diff.outputs.changed == 'true'
+        run: npm run build
+
+      - name: Commit to main
+        if: steps.diff.outputs.changed == 'true'
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+          git add src/assets/data
+          git commit -m "Refresh the astronomical catalogues" \
+            -m "Scheduled re-run of the ETL against the live archives. Gated on the unit suite and a production build in this same run, because a GITHUB_TOKEN push triggers no CI of its own."
+          git push origin HEAD:main
+
+      # The recursion guard that keeps the bot push from triggering `push` workflows also keeps
+      # it from deploying, so the deploy — and a visible CI record on the new commit — are
+      # dispatched explicitly. Dispatch does go through, unlike push events.
+      - name: Redeploy the site, and put checks on the commit
+        if: steps.diff.outputs.changed == 'true'
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          gh workflow run pages.yml --ref main
+          gh workflow run ci.yml --ref main