ci(repo-stats): chart container pulls from ghcr.io alongside clones/stars

GHCR exposes total + 30-day daily-pull counts only in the package page
HTML (no REST or GraphQL endpoint). jgehrcke/github-repo-stats has no
notion of container metrics, so post-process the report after it runs.

New: .github/scripts/ghcr_inject.py
- Scrapes Total downloads (exact integer from title="N", not the K-rounded
  display) and the 30-day sparkline (rect data-merge-count, data-date).
- Merges per-day rows into maziggy/bambuddy/ghcr-pulls.csv on gh-pages.
  Fresh window overwrites overlapping dates, so GitHub's late revisions
  to the last 30 days self-correct; days older than 30 stay frozen at
  whatever was captured while still in-window.
- Patches latest-report/report.html: adds a TOC entry, a Container
  pulls (ghcr.io) section at the top, and a Vega-Lite line+point chart
  whose theme/config is cloned from the existing Total clones chart so
  it inherits the report's look-and-feel.
- Bracketed by HTML-comment markers so re-runs replace rather than
  stack (jgehrcke regenerates report.html every tick; we re-inject).
- Hard-fails if either scrape pattern stops matching — silent fallbacks
  would let the chart freeze without notice.

Workflow: after run-ghrs, checkout source + gh-pages, run the injector,
commit only if the diff is non-empty. Uses the existing contents: write
permission; no new secrets.

.github/workflows/repo-stats.yml

@@ -19,3 +19,40 @@ jobs:
           repository: maziggy/bambuddy
           ghtoken: ${{ secrets.GHRS_GITHUB_API_TOKEN }}
           ghpagesprefix: https://maziggy.github.io/bambuddy
+
+      # Inject ghcr.io container-download stats (cumulative + 30-day
+      # sparkline merged into a sidecar CSV so the chart grows beyond
+      # the 30-day window GHCR exposes). Runs after jgehrcke regenerates
+      # report.html on gh-pages.
+      - name: checkout-source
+        uses: actions/checkout@v4
+        with:
+          path: source
+
+      - name: checkout-gh-pages
+        uses: actions/checkout@v4
+        with:
+          ref: gh-pages
+          path: gh-pages
+
+      - name: inject-ghcr-pulls
+        run: |
+          python3 source/.github/scripts/ghcr_inject.py \
+            --report gh-pages/maziggy/bambuddy/latest-report/report.html \
+            --csv    gh-pages/maziggy/bambuddy/ghcr-pulls.csv \
+            --owner  maziggy \
+            --pkg    bambuddy
+
+      - name: commit-and-push
+        working-directory: gh-pages
+        run: |
+          if [ -z "$(git status --porcelain)" ]; then
+            echo "no changes — skipping commit"
+            exit 0
+          fi
+          git config user.name  "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+          git add maziggy/bambuddy/latest-report/report.html \
+                  maziggy/bambuddy/ghcr-pulls.csv
+          git commit -m "ghcr-pulls: refresh container downloads chart"
+          git push