Add GitHub Actions cross-platform build workflow

Author: adrianpunkt

.github/workflows/build.yml

@@ -0,0 +1,64 @@
+name: Build
+
+on:
+  push:
+    branches:
+      - main
+    tags:
+      - "v*"
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    name: Build ${{ matrix.goos }}-${{ matrix.goarch }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - goos: linux
+            goarch: amd64
+          - goos: linux
+            goarch: arm64
+          - goos: darwin
+            goarch: amd64
+          - goos: darwin
+            goarch: arm64
+          - goos: windows
+            goarch: amd64
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+
+      - name: Build binary
+        shell: bash
+        run: |
+          set -euo pipefail
+          mkdir -p dist
+
+          ext=""
+          if [[ "${{ matrix.goos }}" == "windows" ]]; then
+            ext=".exe"
+          fi
+
+          out="ticktick-${{ matrix.goos }}-${{ matrix.goarch }}${ext}"
+          GOOS="${{ matrix.goos }}" GOARCH="${{ matrix.goarch }}" CGO_ENABLED=0 \
+            go build -trimpath -ldflags="-s -w" -o "dist/${out}" ./cmd/ticktick
+
+          (cd dist && sha256sum "${out}" > "${out}.sha256")
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: ticktick-${{ matrix.goos }}-${{ matrix.goarch }}
+          path: |
+            dist/ticktick-${{ matrix.goos }}-${{ matrix.goarch }}*

README.md

@@ -32,6 +32,14 @@ or
 sudo install -m 0755 ./ticktick /usr/local/bin/ticktick
 ```
 
+## CI Builds
+
+GitHub Actions builds binaries automatically on every push to `main`, tags (`v*`), pull requests, and manual dispatch.
+
+- Open the repository's **Actions** tab.
+- Select the latest **Build** workflow run.
+- Download the artifact matching your platform (for example `ticktick-linux-amd64`).
+
 ## OAuth setup
 
 Create a TickTick app and get: