Add Gitea Actions CI/release workflow

The ci job triggers on every push to main and every pull request; the release job triggers only on tag pushes matching v* and needs the ci job to pass first.

We place the workflow under .github/workflows/ because Gitea Actions is API-compatible with GitHub Actions and discovers workflows in that directory.

The release build command is GOOS=linux GOARCH=amd64 go build -o spark-mcp-linux-amd64 ./main.go, producing the Linux amd64 artifact requested for deployment.

CI runs go build ./..., go vet ./..., go test ./..., and fails if gofmt -l . reports any unformatted files.

Co-Authored-By: Claude <noreply@anthropic.com>

.github/workflows/build.yml

@@ -0,0 +1,66 @@
+# This workflow runs on Gitea Actions, which is API-compatible with GitHub Actions.
+# It performs CI on every push to main and every pull request, and automatically
+# builds and attaches a Linux amd64 release binary when a version tag (v*) is pushed.
+name: CI / Release
+
+on:
+  push:
+    branches:
+      - main
+    tags:
+      - 'v*'
+  pull_request:
+
+jobs:
+  ci:
+    name: CI
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+          cache: true
+
+      - name: Build
+        run: go build ./...
+
+      - name: Vet
+        run: go vet ./...
+
+      - name: Test
+        run: go test ./...
+
+      - name: Check formatting
+        run: |
+          if [ -n "$(gofmt -l .)" ]; then
+            gofmt -l .
+            exit 1
+          fi
+
+  release:
+    name: Release
+    needs: ci
+    if: startsWith(github.ref, 'refs/tags/v')
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+          cache: true
+
+      - name: Build release binary
+        run: GOOS=linux GOARCH=amd64 go build -o spark-mcp-linux-amd64 ./main.go
+
+      - name: Upload release asset
+        uses: softprops/action-gh-release@v2
+        with:
+          files: spark-mcp-linux-amd64
+          generate_release_notes: true