Add GitHub Actions workflow for Windows + macOS builds

Triggers on version tags (v*) or manual dispatch.
Builds .msi/.exe for Windows x64/arm64 and .dmg for macOS
x64/arm64. Creates a draft GitHub release with all artifacts.

.github/workflows/build.yml

@@ -0,0 +1,60 @@
+name: Build
+
+on:
+  workflow_dispatch:
+  push:
+    tags:
+      - 'v*'
+
+permissions:
+  contents: write
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - platform: windows-latest
+            target: x86_64-pc-windows-msvc
+            label: windows-x64
+          - platform: windows-latest
+            target: aarch64-pc-windows-msvc
+            label: windows-arm64
+          - platform: macos-latest
+            target: aarch64-apple-darwin
+            label: macos-arm64
+          - platform: macos-latest
+            target: x86_64-apple-darwin
+            label: macos-x64
+
+    runs-on: ${{ matrix.platform }}
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: oven-sh/setup-bun@v2
+
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          targets: ${{ matrix.target }}
+
+      - name: Install dependencies (Ubuntu)
+        if: matrix.platform == 'ubuntu-latest'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y libwebkit2gtk-4.1-dev libappindicator3-dev librsvg2-dev
+
+      - run: bun install
+
+      - name: Build Tauri
+        uses: tauri-apps/tauri-action@v0
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          TAURI_SIGNING_PRIVATE_KEY: ${{ secrets.TAURI_SIGNING_PRIVATE_KEY || '' }}
+        with:
+          tauriScript: bunx tauri
+          args: --target ${{ matrix.target }}
+          tagName: ${{ github.ref_name }}
+          releaseName: ${{ github.ref_name }}
+          releaseBody: ''
+          releaseDraft: true