Add missing <string> and <vector> includes to HostPlatformColor.h

HostPlatformColor.h uses std::string (in ColorWithSystemEffect and
createSemanticColor) and std::vector but did not include the
corresponding headers, causing build failures when this header is
included before any other header that transitively pulls them in.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Saadnajmi

packages/react-native/ReactCommon/react/renderer/graphics/platform/ios/react/renderer/graphics/HostPlatformColor.h

@@ -10,6 +10,8 @@
 #include <react/renderer/graphics/ColorComponents.h>
 #include <react/utils/hash_combine.h>
 #include <cmath>
+#include <string>
+#include <vector>
 
 namespace facebook::react {