T10: focus in and out reach a program under mode 1004; the window wears the program's title; a bell is logged and silent; the scrollback setting caps history and trims it live; Cmd-F finds in the scrollback with Ely's FindWidget, matches washed, Enter older, Shift-Enter newer, new output searched again

Cargo.toml

@@ -20,6 +20,7 @@ gpui = { package = "gpui-pre", version = "=0.3.8", default-features = false }
 gpui_platform = { package = "gpui-pre-platform", version = "=0.3.8", features = ["font-kit", "wayland", "x11"] }
 log = "0.4"
 polling = "3"
+regex = "1"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 serde_path_to_error = "0.1.20"