Confirmation modal offered when a change needs an owned-server respawn.
Some changes take effect only when the app-owned LangGraph server subprocess
spawns: provider/sandbox extras and --package installs are imported at spawn
time, and a Tavily key saved via /auth binds the web_search tool only at
spawn time. A /restart respawns the subprocess without exiting the TUI, so
rather than make the user type /restart by hand, this modal offers to run
that restart immediately while leaving deferral one keypress away. The title
verb and body are caller-supplied so one modal serves each flow.
