Startup Disk: Do not show if not on UEFI system

```
+ (BOOL)isEFISystemAvailable
{
// Check if this system supports EFI by querying the boot method via sysctl
NSTask *task = [[NSTask alloc] init];
[task setLaunchPath:@"/sbin/sysctl"];
[task setArguments:[NSArray arrayWithObjects:@"-n", @"machdep.bootmethod", nil]];

NSPipe *outputPipe = [NSPipe pipe];
[task setStandardOutput:outputPipe];
[task setStandardError:[NSPipe pipe]];

BOOL isEFIAvailable = NO;

@try {
[task launch];
[task waitUntilExit];

int status = [task terminationStatus];

if (status == 0) {
NSData *outputData = [[outputPipe fileHandleForReading] readDataToEndOfFile];
NSString *bootMethod = [[NSString alloc] initWithData:outputData encoding:NSUTF8StringEncoding];

// Trim whitespace and newlines
bootMethod = [bootMethod stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];

// Check if boot method is UEFI
isEFIAvailable = [bootMethod isEqualToString:@"UEFI"];

[bootMethod release];
}
}
@catch (NSException *exception) {
NSLog(@"StartupDiskPane: EFI availability check failed: %@", exception);
isEFIAvailable = NO;
}

[task release];

return isEFIAvailable;
}

```

But how to tell SystemPreferences.app NOT to show the prefPane in case the test fails?

Review the StartupDiskPane EFI check shown in the issue and how SystemPreferences.app discovers or loads preference panes. Locate the existing entry point that controls pane availability, then verify behavior on UEFI and non-UEFI systems; done means the Startup Disk pane is absent when the check fails. No filename or test is provided, so begin by locating the pane class and its registration metadata.

Written by the indexing model from the issue text.