Light terminal themes: use the terminal's text color too

On a light background (Catppuccin Latte in Ghostty on macOS) the panes
kept palette color 0, a dark grey slab with white text. The probe now also
asks for the text color (OSC 10). Light backgrounds are used as well, with
text, borders and titles in the terminal's text color, input fields and
buttons in a light shade of it, and the active tab drawn in it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019reK4DUGYqDUjniWYJvwUW

internal/ui/app.go

@@ -588,11 +588,11 @@ func (a *App) renderTabs() {
 	for i, v := range a.views {
 		switch {
 		case a.narrow && i == a.active:
-			s += fmt.Sprintf("[black:white]%c %s[-:-] ", v.key, v.name)
+			s += fmt.Sprintf(activeTabTag+"%c %s[-:-] ", v.key, v.name)
 		case a.narrow:
 			s += fmt.Sprintf("[gray]%c %s[-] ", v.key, v.name)
 		case i == a.active:
-			s += fmt.Sprintf("[black:white] %c %s [-:-] ", v.key, v.name)
+			s += fmt.Sprintf(activeTabTag+" %c %s [-:-] ", v.key, v.name)
 		default:
 			s += fmt.Sprintf("[gray] %c %s [-]", v.key, v.name)
 		}