publish: each project's download count, refreshed every hour

publish.yml runs every hour as well as on merges. It sums GitHub's
download_count of each version's release asset into the project's
`downloads` field of index.json, which the launcher and playhorizon.dev/mods
show.

publish and check keep `files/` in the Actions cache, so CI doesn't fetch
every release asset again on each run (each fetch counts as a download).

Co-Authored-By: Claude Opus 5.5 <[email protected]>

.github/workflows/check.yml

@@ -60,6 +60,13 @@ jobs:
             | tee -a "$GITHUB_STEP_SUMMARY" || status=1
           echo '```' >> "$GITHUB_STEP_SUMMARY"
           exit $status
+      # main's files, kept by publish: each download from a release counts as a
+      # player's.
+      - uses: actions/cache/restore@v4
+        with:
+          path: files
+          key: files-${{ hashFiles('head/mods/*.toml') }}
+          restore-keys: files-
       - name: Download its files
         run: base/scripts/fetch.sh head
       - name: Check each new file

.github/workflows/publish.yml

@@ -2,10 +2,14 @@
 # (<id>-<version>/<file>), then index.json and the icons go to GitHub Pages
 # (https://ludovic111.github.io/horizon-mods/index.json), which the launcher and
 # playhorizon.dev/mods read. Nothing is published if any entry fails its checks.
+# Every hour it runs again to refresh each project's `downloads`: GitHub's
+# download counts of its release assets.
 name: publish
 on:
   push:
     branches: [main]
+  schedule:
+    - cron: "23 * * * *"
   workflow_dispatch:
 permissions:
   contents: write
@@ -34,6 +38,13 @@ jobs:
             ~/.cargo/horizon-rev
           key: cargo-horizon-mod-${{ env.HORIZON_REV }}
       - run: scripts/install-tool.sh
+      # Files kept from the last run: GitHub counts every download of a release
+      # asset, so fetching them all again each hour would count as players.
+      - uses: actions/cache@v4
+        with:
+          path: files
+          key: files-${{ hashFiles('mods/*.toml') }}
+          restore-keys: files-
       - run: scripts/fetch.sh .
       - name: Build the index
         run: |
@@ -49,6 +60,19 @@ jobs:
             gh release create "$tag" "$dir/$file" --title "$id $version" --latest=false \
               --notes "Reviewed in the registry: mods/$id.toml. SHA-256 $sha."
           done
+      - name: Download counts
+        run: |
+          # Each version's file is the asset at its URL: a project's downloads
+          # are its files' counts, every version together.
+          gh api --paginate "repos/$GH_REPO/releases?per_page=100" \
+            --jq '.[].assets[] | {key: .browser_download_url, value: .download_count}' \
+            | jq -s from_entries > counts.json
+          jq --slurpfile counts counts.json '
+            .projects |= map(
+              ([.versions[].file.url | $counts[0][.] // 0] | add) as $n
+              | if $n > 0 then .downloads = $n else . end)' site/index.json > index.counted.json
+          mv index.counted.json site/index.json
+          jq -r '.projects[] | "\(.id) \(.downloads // 0)"' site/index.json
       - name: The site
         run: |
           cp -R icons site/icons