ci: add continuous release workflow for rolling VPM pre-releases

vpm/package.sh

@@ -26,7 +26,7 @@ index_url=${VPM_INDEX_URL:-$host/$project/raw/branch/main/vpm/index.json}
 release_base=${VPM_RELEASE_BASE:-}
 
 id=$(jq -r .name "$pkg/package.json")
-version=$(jq -r .version "$pkg/package.json")
+version=${VPM_VERSION:-$(jq -r .version "$pkg/package.json")}
 zip_name="$id-$version.zip"
 : "${release_base:=$host/$project/releases/download/v$version}"
 zip_url="$release_base/$zip_name"

vpm/publish.sh

@@ -14,12 +14,22 @@ root=$(cd "$(dirname "$0")/.." && pwd)
 manifest="$root/csharp/dev.doloro.animator-as-crab/package.json"
 
 id=$(jq -r .name "$manifest")
-version=$(jq -r .version "$manifest")
+version=${VPM_VERSION:-$(jq -r .version "$manifest")}
 zip="$root/vpm/dist/$id-$version.zip"
 
 zip_name=$(basename "$zip")
 [ -f "$zip" ] || { echo "missing $zip; run package.sh first" >&2; exit 1; }
 
+# Delete existing release with same tag if present (needed for rolling tags like continuous)
+existing=$(curl -fsS -H "Authorization: token $TOKEN" \
+  "$SERVER/api/v1/repos/$REPO/releases/tags/$TAG" 2>/dev/null || true)
+if [ -n "$existing" ] && [ "$existing" != 'null' ]; then
+  existing_id=$(jq -r .id <<<"$existing")
+  echo "deleting existing release $existing_id for tag $TAG"
+  curl -fsS -X DELETE -H "Authorization: token $TOKEN" \
+    "$SERVER/api/v1/repos/$REPO/releases/$existing_id"
+fi
+
 release=$(curl -fsS -X POST \
   -H "Authorization: token $TOKEN" -H "Content-Type: application/json" \
   "$SERVER/api/v1/repos/$REPO/releases" \