Add Gitea workflow to pack and publish NuGet packages on push

.gitea/workflows/nuget.yml

@@ -0,0 +1,50 @@
+name: NuGet Package Publish
+
+on:
+  push:
+
+jobs:
+  nuget:
+    runs-on: ubuntu-latest
+
+    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 CBDDC.Libs.slnx
+
+      - name: Pack
+        run: dotnet pack CBDDC.Libs.slnx --configuration Release --no-restore --output artifacts/nuget
+
+      - name: Publish to Gitea NuGet
+        shell: bash
+        env:
+          NUGET_SOURCE_URL: ${{ github.server_url }}/api/packages/${{ github.repository_owner }}/nuget/index.json
+          NUGET_USERNAME: ${{ secrets.NUGET_USERNAME || github.actor }}
+          NUGET_TOKEN: ${{ secrets.NUGET_TOKEN || secrets.GITHUB_TOKEN }}
+        run: |
+          set -euo pipefail
+
+          if [ -z "${NUGET_TOKEN:-}" ]; then
+            echo "NUGET_TOKEN and GITHUB_TOKEN are both unavailable."
+            echo "Configure one of: secrets.NUGET_TOKEN (preferred) or secrets.GITHUB_TOKEN."
+            exit 1
+          fi
+
+          dotnet nuget add source "$NUGET_SOURCE_URL" \
+            --name gitea \
+            --username "$NUGET_USERNAME" \
+            --password "$NUGET_TOKEN" \
+            --store-password-in-clear-text
+
+          find artifacts/nuget -name '*.nupkg' ! -name '*.symbols.nupkg' -print0 | \
+            xargs -0 -I{} dotnet nuget push "{}" \
+              --source gitea \
+              --api-key "$NUGET_TOKEN" \
+              --skip-duplicate