fix(ci): remove broken preprocessor guards from platform WebView files

The #ifdef Q_OS_MACOS / Q_OS_WIN guards wrapped the entire file but
appeared before any Qt include, so without PCH the macros were undefined
and the files were skipped — causing linker errors on CI. CMake already
gates compilation via if(WIN32)/elseif(APPLE).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: nullmastermind

src/widgets/WebViewWidget_mac.mm

@@ -5,8 +5,6 @@
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
-#ifdef Q_OS_MACOS // Entire file is macOS-only
-
 #include "WebViewWidget.h"
 
 #include <QUrl>
@@ -143,5 +141,3 @@ - (void)webView:(WKWebView *)webView didFailProvisionalNavigation:(WKNavigation
 }
 
 #include "WebViewWidget_mac.moc"
-
-#endif // Q_OS_MACOS

src/widgets/WebViewWidget_win.cpp

@@ -5,8 +5,6 @@
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
-#ifdef Q_OS_WIN // Entire file is Windows-only
-
 #include "WebViewWidget.h"
 
 #include <QCoreApplication>
@@ -368,5 +366,3 @@ WebViewWidget *WebViewWidget::create(const QString &appId, const QUrl &url, QWid
 {
     return new WebViewWidgetWin(appId, url, parent);
 }
-
-#endif // Q_OS_WIN