Restore explicit application/x-tar content type for release tarball asset

Folding the tar.gz upload into softprops/action-gh-release's files: input
(commit f6143d18) broke production installs: that action derives the asset
content type via the mime-types library, which maps .tar.gz to
application/gzip. Production installers (refreshInstance.sh,
github-download-release-assets.sh) select the tarball with
select(.content_type=="application/x-tar"), so nothing matched and installs
could not find the release.

Revert to the two explicit actions/upload-release-asset@v1 steps that set
asset_content_type: application/x-tar and text/plain, and add a comment
warning against folding them back in.

Assisted-By: Claude (claude-4.8-opus)

.github/workflows/release.yml

@@ -277,11 +277,33 @@ jobs:
           name: ${{ env.SIMPLE_VERSION_INFO }}
           draft: false
           prerelease: false
-          # Upload the release assets in this same step (newline-separated globs).
-          # action-gh-release infers the content type from each file's extension.
-          files: |
-            ./dist/${{ env.SIMPLE_VERSION_INFO }}/${{ env.SIMPLE_VERSION_INFO }}.tar.gz
-            ./dist/${{ env.SIMPLE_VERSION_INFO }}/release-notes.txt
+      - name: Upload Release Asset tar.gz
+        id: upload-release-asset-tar-gz
+        if: ${{ github.ref == 'refs/heads/main' || github.ref == 'refs/heads/docker-24' || github.ref == 'refs/heads/docker-25' || startsWith(github.ref, 'refs/heads/releases/') }}
+        uses: actions/upload-release-asset@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          # Do NOT fold this into action-gh-release's files: input: that action derives the
+          # content type via the mime-types library, which maps .tar.gz to application/gzip.
+          # Production installers (refreshInstance.sh, github-download-release-assets.sh) select
+          # the tarball with select(.content_type=="application/x-tar"), so the type must be set
+          # explicitly here.
+          upload_url: ${{ steps.create_release.outputs.upload_url }} # This pulls from the CREATE RELEASE step above, referencing it's ID to get its outputs object, which include a `upload_url`. See this blog post for more info: https://jasonet.co/posts/new-features-of-github-actions/#passing-data-to-future-steps
+          asset_path: ./dist/${{ env.SIMPLE_VERSION_INFO }}/${{ env.SIMPLE_VERSION_INFO }}.tar.gz
+          asset_name: ${{ env.SIMPLE_VERSION_INFO }}.tar.gz
+          asset_content_type: application/x-tar
+      - name: Upload Release Asset release_notes.txt
+        id: upload-release-asset-release-notes-txt
+        if: ${{ github.ref == 'refs/heads/main' || github.ref == 'refs/heads/docker-24' || github.ref == 'refs/heads/docker-25' || startsWith(github.ref, 'refs/heads/releases/') }}
+        uses: actions/upload-release-asset@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          upload_url: ${{ steps.create_release.outputs.upload_url }} # This pulls from the CREATE RELEASE step above, referencing it's ID to get its outputs object, which include a `upload_url`. See this blog post for more info: https://jasonet.co/posts/new-features-of-github-actions/#passing-data-to-future-steps
+          asset_path: ./dist/${{ env.SIMPLE_VERSION_INFO }}/release-notes.txt
+          asset_name: release-notes.txt
+          asset_content_type: text/plain
       - name: Trigger CI job
         env:
           CI_JOB_USERNAME: ${{ vars.CI_JOB_USERNAME }}