ci: fail release on real extension publish errors

The `|| echo "Version may already exist, skipping"` fallback masked
genuine vsce/ovsx failures (reserved name, reserved displayName, auth),
leaving the workflow green while nothing published. Replace it with a
version pre-check: skip publishing only when that exact version is
already on the registry (vsce show / Open VSX API), and let any other
failure fail the job.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: Peter Stenger

.github/workflows/release.yml

@@ -86,7 +86,15 @@ jobs:
       - name: Publish to VS Code Marketplace
         if: github.event_name == 'release'
         working-directory: lsp
-        run: vsce publish --packagePath htmlmustache-lsp.vsix || echo "Version may already exist, skipping"
+        # Skip only if this exact version is already published; let any other
+        # vsce failure (e.g. reserved name/displayName, auth) fail the job.
+        run: |
+          read -r EXT VERSION < <(node -p "const p=require('./package.json'); p.publisher+'.'+p.name+' '+p.version")
+          if vsce show "$EXT" --json 2>/dev/null | node -e "const v=require('fs').readFileSync(0,'utf8'); let j; try{j=JSON.parse(v)}catch{process.exit(1)} process.exit((j.versions||[]).some(x=>x.version===process.argv[1])?0:1)" "$VERSION"; then
+            echo "::notice::$EXT@$VERSION already on VS Marketplace, skipping publish"
+          else
+            vsce publish --packagePath htmlmustache-lsp.vsix
+          fi
         env:
           VSCE_PAT: ${{ secrets.VSCE_PAT }}
 
@@ -96,6 +104,15 @@ jobs:
       - name: Publish to Open VSX Registry
         if: github.event_name == 'release'
         working-directory: lsp
-        run: ovsx publish htmlmustache-lsp.vsix || echo "Version may already exist, skipping"
+        # Skip only if this exact version is already published (API returns 200);
+        # let any other ovsx failure (e.g. auth, namespace) fail the job.
+        run: |
+          read -r NS NAME VERSION < <(node -p "const p=require('./package.json'); p.publisher+' '+p.name+' '+p.version")
+          code=$(curl -s -o /dev/null -w '%{http_code}' "https://open-vsx.org/api/$NS/$NAME/$VERSION")
+          if [ "$code" = "200" ]; then
+            echo "::notice::$NS.$NAME@$VERSION already on Open VSX, skipping publish"
+          else
+            ovsx publish htmlmustache-lsp.vsix
+          fi
         env:
           OVSX_PAT: ${{ secrets.OVSX_PAT }}