Switch to gRPC client in Swift app

.github/workflows/release-apple.yml

@@ -22,6 +22,7 @@ jobs:
           - aarch64-apple-darwin
     env:
       DEVELOPER_DIR: /Applications/Xcode_16.0.app/Contents/Developer
+      PROTOC_PATH: /opt/homebrew/bin/protoc
     steps:
     - name: Checkout
       uses: actions/checkout@v4
@@ -47,6 +48,9 @@ jobs:
       uses: dtolnay/rust-toolchain@stable
       with:
         targets: ${{ join(matrix.rust-targets, ', ') }}
+    - name: Install Protobuf
+      shell: bash
+      run: brew install protobuf
     - name: Configure Version
       id: version
       shell: bash