add new workflow [publish]

Author: itsAudioo

.github/workflows/build-and-publish.yml

@@ -0,0 +1,43 @@
+name: Publish NuGet (on [publish] commit)
+
+on:
+  push:
+    branches:
+      - "**"
+
+jobs:
+  publish:
+    if: contains(github.event.head_commit.message, '[publish]')
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup .NET
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: "10.0.x"
+
+      - name: Restore
+        run: |
+          dotnet restore ./S2PluginKit.slnx || dotnet restore ./S2PluginKit.csproj
+
+      - name: Build (Release)
+        run: |
+          dotnet build ./S2PluginKit.slnx -c Release --no-restore || \
+          dotnet build ./S2PluginKit.csproj -c Release --no-restore
+
+      - name: Verify package exists
+        run: |
+          ls -la artifacts
+          test -f artifacts/*.nupkg
+
+      - name: Push package to NuGet.org
+        run: |
+          dotnet nuget push "artifacts/*.nupkg" \
+            --source https://api.nuget.org/v3/index.json \
+            --api-key ${{ secrets.NUGET_API_KEY }} \
+            --skip-duplicate