test: cover native stdin close over wss

scripts/windows/native-test

@@ -157,6 +157,28 @@ assert_context() {
     fail "$label did not reach terminal success"
 }
 
+assert_stdin_close() {
+    issued=$(rvc run --background --shell cmd "$client_id" 'set /p RVBOX_STDIN= & echo RVBOX_STDIN_%RVBOX_STDIN%' 2>&1) || fail "stdin command admission failed: $issued"
+    issue=$(printf '%s\n' "$issued" | awk 'NR == 1 { print $1 }')
+    case $issue in ????????-????-7???-????-????????????) ;; *) fail "stdin command returned invalid issue UUID: $issued" ;; esac
+    # The command remains running until the durable StdinWrite reaches the
+    # native service. Use the public rvc controls, not guest-side injection.
+    rvc append "$client_id" "$issue" RVBOX_NATIVE_INPUT >/dev/null || fail "stdin append failed"
+    rvc close-stdin "$client_id" "$issue" >/dev/null || fail "stdin close failed"
+    attempt=0
+    while [ "$attempt" -lt 45 ]; do
+        result=$(rvc stat "$client_id" "$issue" 2>/dev/null || true)
+        if printf '%s\n' "$result" | grep -q 'lifecycle=COMMAND_SUCCEEDED'; then
+            printf '%s\n' "$result" >"$fixture_dir/stdin-close.stat"
+            printf 'passed stdin-close issue=%s\n' "$issue"
+            return 0
+        fi
+        case $result in *'lifecycle=COMMAND_FAILED'*|*'lifecycle=COMMAND_REJECTED'*|*'lifecycle=COMMAND_TERMINATED'*) fail "stdin command did not succeed: $result" ;; esac
+        attempt=$((attempt + 1)); sleep 1
+    done
+    fail "stdin command did not reach terminal success"
+}
+
 collect() {
     if [ "$vm_prepared" = yes ]; then
         "$repo_root/scripts/windows/test-host" collect --run-id "$run_id" || true
@@ -201,6 +223,7 @@ case $action in
         "$repo_root/scripts/windows/test-host" install --run-id "$run_id"
         "$repo_root/scripts/windows/test-host" run --run-id "$run_id" --endpoint "$endpoint_host:$port"
         wait_client
+        assert_stdin_close
         assert_context active-user no active-user
         assert_context active-user-elevated yes active-user-elevated
         "$repo_root/scripts/windows/test-host" run --run-id "$run_id" --fail-contexts ACTIVE_USER_ELEVATED

test/windowsnative/native_fixture_test.go

@@ -28,6 +28,9 @@ func TestNativeFixtureAssets_HP_HARNESS_20(t *testing.T) {
 		"scripts/windows/test-host\" prepare",
 		"ACTIVE_USER_ELEVATED,ACTIVE_SYSTEM",
 		"assert_context local-service no local-service",
+		"assert_stdin_close",
+		"rvc append \"$client_id\" \"$issue\" RVBOX_NATIVE_INPUT",
+		"rvc close-stdin \"$client_id\" \"$issue\"",
 		"clean --purge --yes",
 		"RVBOX_NATIVE_ENDPOINT_HOST",
 		"test/linux-server/compose.yaml",