feat: add GitHub Actions workflow for building Linux application

.github/workflows/build-linux.yml

@@ -0,0 +1,71 @@
+name: Build Linux
+
+on:
+  push:
+    branches: [main, master]
+  pull_request:
+    branches: [main, master]
+
+jobs:
+  build-linux:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: "1.24"
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+
+      - name: Install system dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y \
+            build-essential \
+            pkg-config \
+            libgtk-3-dev \
+            libwebkit2gtk-4.0-dev \
+            libasound2-dev \
+            libayatana-appindicator3-dev
+
+      - name: Install Wails CLI
+        run: go install github.com/wailsapp/wails/v2/cmd/wails@latest
+
+      - name: Install frontend dependencies
+        run: npm install
+        working-directory: frontend
+
+      - name: Determine version
+        id: version
+        run: |
+          if [ -f scripts/VERSION ]; then
+            VERSION=$(head -n1 scripts/VERSION | tr -d '\r\n' | xargs)
+          fi
+          if [ -z "$VERSION" ]; then
+            VERSION="dev"
+          fi
+          echo "app_version=$VERSION" >> "$GITHUB_OUTPUT"
+
+      - name: Fix npm bin permissions
+        run: chmod +x frontend/node_modules/.bin/* 2>/dev/null || true
+
+      - name: Build app
+        run: |
+          WAILS_WEBKIT_TAGS=""
+          if pkg-config --exists webkit2gtk-4.1 2>/dev/null; then
+            WAILS_WEBKIT_TAGS="-tags webkit2_41"
+          fi
+          wails build -platform linux/amd64 -clean $WAILS_WEBKIT_TAGS -ldflags "-X main.AppVersion=${{ steps.version.outputs.app_version }}"
+
+      - name: Upload binary
+        uses: actions/upload-artifact@v4
+        with:
+          name: wis-free-v3-linux-amd64
+          path: build/bin/wis-free-v3