feat: publish standalone installer archives

.github/workflows/rust-release.yml

@@ -540,13 +540,41 @@ jobs:
             --release-version "$RELEASE_VERSION" \
             --package codex \
             --package codex-responses-api-proxy \
-            --package codex-sdk
+            --package codex-sdk \
+            --standalone-output-dir dist/installer
 
       - name: Stage installer scripts
         run: |
           cp scripts/install/install.sh dist/install.sh
           cp scripts/install/install.ps1 dist/install.ps1
 
+      - name: Stage installer checksums
+        env:
+          RELEASE_VERSION: ${{ steps.release_name.outputs.name }}
+        run: |
+          set -euo pipefail
+
+          checksums="dist/codex-installer_SHA256SUMS"
+          found=false
+          : > "$checksums"
+
+          for archive in dist/installer/codex-standalone-*-"${RELEASE_VERSION}".tar.gz; do
+            if [[ ! -e "$archive" ]]; then
+              continue
+            fi
+
+            found=true
+            digest="$(sha256sum "$archive" | awk '{print $1}')"
+            printf '%s  %s\n' "$digest" "$(basename "$archive")" >> "$checksums"
+          done
+
+          if [[ "$found" != true ]]; then
+            echo "No Codex standalone installer archives found for ${RELEASE_VERSION}."
+            exit 1
+          fi
+
+          sort -k2,2 "$checksums" -o "$checksums"
+
       - name: Create GitHub Release
         uses: softprops/action-gh-release@153bb8e04406b158c6c84fc1615b65b24149a1fe # v2
         with: