ci: add Gitea Actions workflow for npm publishing

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitea/workflows/publish.yml

@@ -0,0 +1,39 @@
+name: Build & Publish
+
+on:
+  push:
+    branches: [main]
+    tags: ['v*']
+
+jobs:
+  publish:
+    runs-on: linux-arm64
+    container:
+      image: node:22-bookworm-slim
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run tests
+        run: npx vitest run
+
+      - name: Build library
+        run: npm run build:lib
+
+      - name: Publish package
+        run: |
+          if [[ "$GITHUB_REF" == refs/tags/v* ]]; then
+            VERSION="${GITHUB_REF_NAME#v}"
+            npm version "$VERSION" --no-git-tag-version
+            TAG="latest"
+          else
+            SHORT_SHA=$(echo "$GITHUB_SHA" | head -c 7)
+            DATE=$(date +%Y%m%d)
+            npm version "0.0.0-snapshot.${DATE}.${SHORT_SHA}" --no-git-tag-version
+            TAG="dev"
+          fi
+          echo '@cameleer:registry=https://gitea.siegeln.net/api/packages/cameleer/npm/' > .npmrc
+          echo '//gitea.siegeln.net/api/packages/cameleer/npm/:_authToken=${{ secrets.REGISTRY_TOKEN }}' >> .npmrc
+          npm publish --tag "$TAG"