fix: correct RAM usage (#2019)

Co-authored-by: sangjanai <sang@jan.ai>

Author: vansangpfiev

engine/utils/hardware/ram_info.h

@@ -17,12 +17,12 @@ inline Memory GetMemoryInfo() {
   hwinfo::Memory m;
 #if defined(__APPLE__) && defined(__MACH__)
   int64_t total_memory = 0;
-  int64_t used_memory = 0;
+  int64_t avail_memory = 0;
 
   size_t length = sizeof(total_memory);
   sysctlbyname("hw.memsize", &total_memory, &length, NULL, 0);
 
-  // Get used memory (this is a rough estimate)
+  // Get avail memory (this is a rough estimate)
   vm_size_t page_size;
   mach_msg_type_number_t count = HOST_VM_INFO_COUNT;
 
@@ -31,12 +31,10 @@ inline Memory GetMemoryInfo() {
 
   if (host_statistics(mach_host_self(), HOST_VM_INFO, (host_info_t)&vm_stat,
                       &count) == KERN_SUCCESS) {
-    used_memory =
-        (vm_stat.active_count + vm_stat.inactive_count + vm_stat.wire_count) *
-        page_size;
+    avail_memory = (vm_stat.free_count + vm_stat.inactive_count) * page_size;
   }
   return Memory{.total_MiB = ByteToMiB(total_memory),
-                .available_MiB = ByteToMiB(total_memory - used_memory)};
+                .available_MiB = ByteToMiB(avail_memory)};
 #elif defined(__linux__) || defined(_WIN32)
   return Memory{.total_MiB = ByteToMiB(m.total_Bytes()),
                 .available_MiB = ByteToMiB(m.available_Bytes())};