Add brand-specific update channel and environment configuration

- Updated `brand_config.py` to include `WEBDROP_UPDATE_CHANNEL` in the environment variables.
- Enhanced `build_macos.sh` to create a bundled `.env` file with brand-specific defaults, including the update channel.
- Implemented a method in `build_windows.py` to create a bundled `.env` file for Windows builds, incorporating brand-specific runtime defaults.
- Modified `config.py` to ensure the application can locate the `.env` file in various installation scenarios.
- Added unit tests in `test_config.py` to verify the loading of the bootstrap `.env` from the PyInstaller runtime directory.
- Generated new WiX object and script files for the Windows installer, including application shortcuts and registry entries.

build/scripts/build_macos.sh

@@ -200,8 +200,21 @@ build_executable() {
     log_info "Building macOS executable with PyInstaller..."
     echo ""
 
+    # Create bundled runtime .env with brand defaults so first launch
+    # uses brand-specific app name and config directory.
+    BUNDLED_ENV_FILE="$TEMP_BUILD/.env"
+    cp "$ENV_FILE" "$BUNDLED_ENV_FILE"
+    {
+        echo ""
+        echo "# Brand-specific defaults added during packaging"
+        echo "APP_NAME=\"$WEBDROP_APP_DISPLAY_NAME\""
+        echo "BRAND_ID=\"$WEBDROP_BRAND_ID\""
+        echo "APP_CONFIG_DIR_NAME=\"$WEBDROP_CONFIG_DIR_NAME\""
+        echo "UPDATE_CHANNEL=\"$WEBDROP_UPDATE_CHANNEL\""
+    } >> "$BUNDLED_ENV_FILE"
+
     # Export env file for spec file to pick up
-    export WEBDROP_ENV_FILE="$ENV_FILE"
+    export WEBDROP_ENV_FILE="$BUNDLED_ENV_FILE"
     export WEBDROP_VERSION="$VERSION"
     export WEBDROP_BUNDLE_ID="$BUNDLE_IDENTIFIER"