It's a TUI if it uses text to build those elements.
No. All you've done is make a low-resolution GUI.
Yeah, that's the point. Why did you think you needed to say it?
It's a GUI that works over SSH. There is a very valid use case for that.
Would you say old DOS applications like Borland's Turbo series of compilers were not TUIs? They ran in the console but had menus, mouse support, dialog boxes, etc...
How about those text games that used ASCII art and you typed in commands like "look" and "go north"?
I would say using text mode is the primary requirement for a TUI. The other requirement being some kind of human-machine connection, IE a User Interface.
TUI means "Terminal User Interface" or "Text User Interface"
A GUI that is built with Text, and intended to be used in a Terminal, is what a TUI is, colloquially AND definitionally.
What do you think qualifies as a TUI?