Fix Windows: use sys/time.h for gettimeofday, remove custom implementation

lib/platform_compat.h

@@ -39,24 +39,8 @@
         #define POLLPRI 0x0002
     #endif
     
-    // gettimeofday for Windows (timezone already defined in time.h)
-    // Note: MSYS2 already has gettimeofday in sys/time.h, so we skip it here
-    #if !defined(HAVE_GETTIMEOFDAY) && !defined(__MINGW32__)
-    static inline int gettimeofday(struct timeval *tv, void *tz) {
-        (void)tz;
-        if (tv) {
-            FILETIME ft;
-            ULARGE_INTEGER ull;
-            GetSystemTimeAsFileTime(&ft);
-            ull.LowPart = ft.dwLowDateTime;
-            ull.HighPart = ft.dwHighDateTime;
-            // Convert from 100-nanosecond intervals since 1601 to Unix epoch
-            tv->tv_sec = (long)(ull.QuadPart / 10000000ULL - 11644473600ULL);
-            tv->tv_usec = (long)((ull.QuadPart % 10000000ULL) / 10);
-        }
-        return 0;
-    }
-    #endif
+    // gettimeofday for Windows (use system implementation if available)
+    #include <sys/time.h>
     
     // Pipe creation for Windows
     static inline int platform_pipe(int pipefd[2]) {