ci: publish latest only from stable releases and scope workflow tokens

A manual run of the release image workflow tagged `latest` on whatever
ref it was dispatched from, and the demo deploy and every Watchtower
install follow `latest`. It now moves only for a published stable
release or a dispatch on a stable `v*` tag.

- `static-lite.yml` gave the whole workflow `contents: write`, including
  the build job that runs pull-request code. The build is read-only
  now; a separate release job with no checkout uploads the zips.
- `docker-publish.yml` passes the ref name through `env` instead of
  interpolating it into the shell script.

.github/workflows/docker-publish-releases.yml

@@ -1,5 +1,8 @@
 name: Publish Docker Image on Release
 
+# `latest` moves only for a published stable release, or for a manual run
+# dispatched on a stable release tag (to rebuild one). A dispatch on a
+# branch builds nothing that the demo deploy or Watchtower users follow.
 on:
   release:
     types: [published]
@@ -101,7 +104,7 @@ jobs:
         with:
           images: ${{ env.IMAGE_NAME }}
           tags: |
-            type=raw,value=latest,enable=${{ github.event_name != 'release' || !github.event.release.prerelease }}
+            type=raw,value=latest,enable=${{ (github.event_name == 'release' && !github.event.release.prerelease) || (github.event_name == 'workflow_dispatch' && startsWith(github.ref, 'refs/tags/v') && !contains(github.ref_name, '-')) }}
             type=semver,pattern=v{{version}}
             type=semver,pattern={{version}}
             type=semver,pattern=v{{major}}.{{minor}}
@@ -212,7 +215,7 @@ jobs:
           flavor: |
             suffix=-always,onlatest=true
           tags: |
-            type=raw,value=latest,enable=${{ github.event_name != 'release' || !github.event.release.prerelease }}
+            type=raw,value=latest,enable=${{ (github.event_name == 'release' && !github.event.release.prerelease) || (github.event_name == 'workflow_dispatch' && startsWith(github.ref, 'refs/tags/v') && !contains(github.ref_name, '-')) }}
             type=semver,pattern=v{{version}}
             type=semver,pattern={{version}}
             type=semver,pattern=v{{major}}.{{minor}}

.github/workflows/docker-publish.yml

@@ -29,11 +29,14 @@ jobs:
     steps:
       - name: Set image name
         id: set
+        env:
+          REF_NAME: ${{ github.ref_name }}
+          REPOSITORY: ${{ github.repository }}
         run: |
-          if [ "${{ github.ref_name }}" = "main" ]; then
-            echo "image_name=ghcr.io/${{ github.repository }}-beta" >> $GITHUB_OUTPUT
+          if [ "$REF_NAME" = "main" ]; then
+            echo "image_name=ghcr.io/${REPOSITORY}-beta" >> "$GITHUB_OUTPUT"
           else
-            echo "image_name=ghcr.io/${{ github.repository }}-${{ github.ref_name }}" >> $GITHUB_OUTPUT
+            echo "image_name=ghcr.io/${REPOSITORY}-${REF_NAME}" >> "$GITHUB_OUTPUT"
           fi
 
   build:

.github/workflows/static-lite.yml

@@ -42,7 +42,7 @@ on:
         default: false
 
 permissions:
-  contents: write
+  contents: read
 
 jobs:
   build:
@@ -98,21 +98,36 @@ jobs:
           echo "ZIP=${ZIP}" >> "$GITHUB_ENV"
           ls -la "${ZIP}"
 
-      - name: Upload release asset
-        if: github.event_name == 'release'
-        env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          TAG_NAME: ${{ github.event.release.tag_name }}
-        run: gh release upload "$TAG_NAME" "$ZIP" --clobber
-
       - name: Upload artifact
-        if: github.event_name != 'release'
         uses: actions/upload-artifact@v4
         with:
           name: bulwark-lite-${{ matrix.target }}
           path: ${{ env.ZIP }}
           retention-days: 7
 
+  release:
+    # The only job with a write token, and it runs no checked-out code.
+    needs: build
+    if: github.event_name == 'release'
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    permissions:
+      contents: write
+    steps:
+      - name: Download zips
+        uses: actions/download-artifact@v4
+        with:
+          pattern: bulwark-lite-*
+          path: zips
+          merge-multiple: true
+
+      - name: Upload release assets
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GH_REPO: ${{ github.repository }}
+          TAG_NAME: ${{ github.event.release.tag_name }}
+        run: gh release upload "$TAG_NAME" zips/*.zip --clobber
+
   smoke:
     # Boots the demo export on a plain static server and drives it with
     # Playwright: login, open a thread, switch surfaces, reload a deep link.