Measure cached Dosh attach fast path

scripts/ci-docker-ssh-bench.sh

@@ -31,7 +31,7 @@ for _ in 1 2 3 4 5; do
 done
 
 ssh-keyscan -p "$ssh_port" 127.0.0.1 > "$workdir/known_hosts"
-mkdir -p "$workdir/home" "$workdir/home-controlmaster" "$workdir/home-mosh"
+mkdir -p "$workdir/home" "$workdir/home-controlmaster" "$workdir/home-cached" "$workdir/home-mosh"
 
 if ! HOME="$workdir/home" target/release/dosh-bench \
     --server bench@127.0.0.1 \
@@ -64,6 +64,22 @@ if ! HOME="$workdir/home-controlmaster" target/release/dosh-bench \
   exit 1
 fi
 
+if ! HOME="$workdir/home-cached" target/release/dosh-bench \
+    --server bench@127.0.0.1 \
+    --ssh-port "$ssh_port" \
+    --dosh-port "$dosh_port" \
+    --ssh-key "$workdir/id_ed25519" \
+    --ssh-known-hosts "$workdir/known_hosts" \
+    --ssh-auth-command /usr/local/bin/dosh-auth \
+    --iterations 10 \
+    --warm-cache \
+    --skip-ssh-baseline \
+    --assert-dosh-max-ms "${DOSH_BENCH_CACHED_MAX_MS:-25}"; then
+  docker logs "$container_id" || true
+  docker exec "$container_id" sh -lc 'cat /tmp/dosh-server.log 2>/dev/null || true' || true
+  exit 1
+fi
+
 if [ "${DOSH_BENCH_INCLUDE_MOSH:-0}" = "1" ]; then
   if ! HOME="$workdir/home-mosh" target/release/dosh-bench \
       --server bench@127.0.0.1 \