* fix(injection): use Ctrl+Shift+V when pasting into terminals
Clipboard injection always sent Ctrl+V, which most terminal emulators
ignore. Detect standalone terminal windows and send Ctrl+Shift+V, with a
Settings override for nested IDE panels that window-class detection cannot see.
* fix(injection): fail closed when terminal window probe is mocked
Clipboard tests patch text_injector.subprocess.run, which replaces
stdlib subprocess.run. Window detection now ignores non-string probe
output so injection still uses Ctrl+V instead of raising TypeError.
* docs: fix overclaimed terminal auto-detect in USER_GUIDE
Auto-detect only runs on X11 and on Hyprland, Sway, and niri. GNOME and
KDE Wayland stay on Ctrl+V unless you set Clipboard Paste Shortcut to
Ctrl+Shift+V.
