stdout_driver_class

Return a Textual Unix driver class that renders through stdout.

Textual's LinuxDriver writes every frame to sys.__stderr__, while TerminalStderrGuard points fd 2 at /dev/null — so under an active guard the stock driver renders the whole TUI into the void. The returned subclass aims driver output at sys.__stdout__ instead, which the guard leaves alone and which _stderr_targets_stdout has already proven is the same terminal. Callers must not install the guard without also applying this.

Like the patches in _textual_patches, this reaches into private Textual state and so refuses to guess when the ground shifts: it returns None when stdout cannot carry the TUI or when the caller's own driver choice must win, and the subclass raises rather than rendering blind if Textual ever stops keeping its output stream in _file.