ci: add desktop app build workflow

.github/workflows/build-desktop.yml

@@ -0,0 +1,114 @@
+name: Build Desktop Apps
+
+on:
+  workflow_dispatch:
+    inputs:
+      build_windows:
+        description: Build the Windows package
+        type: boolean
+        default: true
+      build_macos:
+        description: Build the macOS package
+        type: boolean
+        default: true
+      refresh_flet:
+        description: Re-download the Flet desktop archive
+        type: boolean
+        default: false
+
+permissions:
+  contents: read
+
+concurrency:
+  group: build-desktop-${{ github.ref }}
+  cancel-in-progress: false
+
+jobs:
+  build-windows:
+    name: Build Windows
+    if: ${{ inputs.build_windows }}
+    runs-on: windows-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.10"
+          cache: pip
+          cache-dependency-path: requirements.txt
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install -r requirements.txt
+          pip install pyinstaller
+
+      - name: Prepare bundled FFmpeg
+        run: python scripts/download_ffmpeg.py --platform windows
+
+      - name: Prepare bundled Node.js
+        run: python scripts/download_nodejs.py --platform windows --windows-arch x64
+
+      - name: Build app
+        run: |
+          $refreshArg = if ("${{ inputs.refresh_flet }}" -eq "true") { "--refresh-flet" } else { "" }
+          python scripts/build.py --platform windows $refreshArg
+
+      - name: Package zip
+        run: Compress-Archive -Path dist/StreamCap/* -DestinationPath dist/StreamCap-windows.zip -Force
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: StreamCap-windows
+          path: dist/StreamCap-windows.zip
+          if-no-files-found: error
+
+  build-macos:
+    name: Build macOS
+    if: ${{ inputs.build_macos }}
+    runs-on: macos-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.10"
+          cache: pip
+          cache-dependency-path: requirements.txt
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install -r requirements.txt
+          pip install pyinstaller
+
+      - name: Prepare bundled FFmpeg
+        run: python scripts/download_ffmpeg.py --platform macos
+
+      - name: Prepare bundled Node.js
+        run: python scripts/download_nodejs.py --platform macos
+
+      - name: Build app
+        run: |
+          REFRESH_ARG=""
+          if [ "${{ inputs.refresh_flet }}" = "true" ]; then
+            REFRESH_ARG="--refresh-flet"
+          fi
+          python scripts/build.py --platform macos $REFRESH_ARG
+
+      - name: Package dmg
+        run: hdiutil create -volname "StreamCap" -srcfolder "dist/StreamCap.app" -ov -format UDZO "dist/StreamCap-macos.dmg"
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: StreamCap-macos
+          path: dist/StreamCap-macos.dmg
+          if-no-files-found: error