Terminal shows an empty window and then a conhost window opens after 30s when used as default terminal application

### Windows Terminal version

1.18.3181.0

### Windows build number

10.0.26020.1000

### Other Software

_No response_

### Steps to reproduce

1. Run cmd from the Start box or Start Menu.

### Expected Behavior

1. Windows Terminal to open with the specified console application.

### Actual Behavior

1. A Windows Terminal opened without any session in it.
2. 30 seconds pass.
3. A fallback conhost appears with my desired program.
4. Upon exiting the desired program and conhost closing, the Windows Terminal launches a PowerShell session.

See this video: https://github.com/microsoft/terminal/assets/82626/bd07a775-f033-43dc-b8a8-7c793c90fcd1

Start by reproducing the launch flow described: run cmd from the Start box or Start Menu with Windows Terminal set as the default terminal application. Investigate the terminal startup path and the 30-second fallback to conhost, then verify that the requested console application opens directly in Windows Terminal without an empty window or delayed fallback.

Written by the indexing model from the issue text.