Fix three Windows-specific compile errors

- logger.cpp: use localtime_s on Windows (reversed arg order vs localtime_r)
- process.hpp: drop constexpr on INVALID_PROCESS (INVALID_HANDLE_VALUE is a
  reinterpret_cast, not valid in constexpr context)
- world_packets.hpp: push/pop ERROR macro around CharCreateResult enum to avoid
  clash with wingdi.h #define ERROR 0

include/game/world_packets.hpp

@@ -176,6 +176,11 @@ public:
 // ============================================================
 
 // WoW 3.3.5a ResponseCodes for character creation (from ResponseCodes enum)
+// Windows wingdi.h defines ERROR as 0; undefine it for this enum scope.
+#ifdef _WIN32
+#pragma push_macro("ERROR")
+#undef ERROR
+#endif
 enum class CharCreateResult : uint8_t {
     // Success codes
     SUCCESS              = 0x2F,  // CHAR_CREATE_SUCCESS
@@ -224,6 +229,9 @@ enum class CharCreateResult : uint8_t {
     NAME_RUSSIAN_SILENT_AT_BEGIN_OR_END = 0x66,  // CHAR_NAME_RUSSIAN_SILENT_CHARACTER_AT_BEGINNING_OR_END
     NAME_DECLENSION_DOESNT_MATCH = 0x67,  // CHAR_NAME_DECLENSION_DOESNT_MATCH_BASE_NAME
 };
+#ifdef _WIN32
+#pragma pop_macro("ERROR")
+#endif
 
 struct CharCreateData {
     std::string name;

include/platform/process.hpp

@@ -13,7 +13,7 @@
   #include <windows.h>
 
   using ProcessHandle = HANDLE;
-  inline constexpr ProcessHandle INVALID_PROCESS = INVALID_HANDLE_VALUE;
+  inline const ProcessHandle INVALID_PROCESS = INVALID_HANDLE_VALUE;
 
 #else
   #include <sys/types.h>

src/core/logger.cpp

@@ -35,7 +35,11 @@ void Logger::log(LogLevel level, const std::string& message) {
         now.time_since_epoch()) % 1000;
 
     std::tm tm;
+#ifdef _WIN32
+    localtime_s(&tm, &time);
+#else
     localtime_r(&time, &tm);
+#endif
 
     // Format: [YYYY-MM-DD HH:MM:SS.mmm] [LEVEL] message
     std::ostringstream line;