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.lock

@@ -1766,6 +1766,7 @@ dependencies = [
  "objc",
  "polling",
  "raw-window-handle",
+ "regex",
  "rustix-openpty",
  "serde",
  "serde_json",