Windows Terminal startup delay when launched via CreateProcess

### Windows Terminal version

1.23.20211.0

### Windows build number

10.0.26200.7634

### Other Software

Visual Studio 2026 18.2.0

### Steps to reproduce

- Open Visual Studio and create a new MFC App with the default settings
- Change the implementation of the `OnAppAbout()` function to
```
STARTUPINFOA si;
ZeroMemory(&si, sizeof(si));
si.cb = sizeof(si);

PROCESS_INFORMATION pi;
ZeroMemory(&pi, sizeof(pi));

char CmdLine[] = "cmd.exe";

CreateProcessA(NULL, CmdLine, NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi);
WaitForSingleObject(pi.hProcess, INFINITE);

CloseHandle(pi.hThread);
CloseHandle(pi.hProcess);
```
- Build and run the app
- Click _Help > About MFCApplication..._
- Observe a delay of a few seconds before the terminal appears
- Change _Settings > System > Advanced > Terminal_ setting to _Windows Console Host_
- Click _Help > About MFCApplication...._
- Observe that the terminal appears almost instantly

### Expected Behavior

When launching the new Windows Terminal, the window should open quickly, similar to the legacy one.

### Actual Behavior

When launching the new Windows Terminal, there is a noticeable delay before the window appears.

Start by reproducing the delay with the provided MFC App and CreateProcessA sequence, then compare it with Windows Console Host selected under Settings > System > Advanced > Terminal. No source files, tests, or entry points are named; done means identifying the startup delay and making Windows Terminal appear promptly when launched this way.

Written by the indexing model from the issue text.