console: one sequential loop; host tests in one binary

The console reads a line, runs it to the end, and prints the result,
with and without a terminal. Notifications print while a command runs.
Ctrl-C during a command stops only the wait. 314 lines (was 480).

All host integration tests are modules of cli/tests/host/, so they run
in one parallel pool, and the probes build once. Warm, the 184 host
tests take 24 s (was about 45 s as seven binaries in sequence), and
cargo test --workspace takes 45 s.

cli/src/main.rs

@@ -186,7 +186,7 @@ async fn main() -> Result<std::process::ExitCode> {
             let exit = tokio::select! {
                 _=host.exit_requested()=>true,
                 _=term.recv()=>false,
-                _=interrupt.recv()=>false,
+                _=interrupt.recv(), if cli.headless=>false,
                 result = console, if !cli.headless => {
                     console_result=result;
                     false