test: wait for app readiness before late session injection (#4224)

Root cause:
The API socket is bound before App evaluates session restore. Waiting only
for that socket lets the late-session test inject its file during startup,
so the server may load it normally instead of exercising late-file recovery.
The missing backup then fails an otherwise correct persistence assertion.

Fix:
Wait for a read-only workspace-list request to pass through App and assert
that the workspace list is still empty before injecting the session file.
Keep the existing autosave deadline and byte-for-byte backup assertion.
Add no sleeps, retries, longer timeouts or production changes.

Validation:
The original assertion fails with unchanged master. With the barrier, five
independent runs pass. Full native just ci passes 3624 Rust tests with six
default skips, formatting, all-target Clippy, 112 maintenance tests, six
architecture tests and 39 integration-asset tests. All seven docs contract
tests pass. Local Windows cross-lint was not run because its SDK is absent.

Co-authored-by: JJ Liebig <jonathan.liebig@gmail.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/tests/cli/sessions.rs b/tests/cli/sessions.rs
index 717f02ef..66232ce2 100644
--- a/tests/cli/sessions.rs
+++ b/tests/cli/sessions.rs
@@ -706,6 +706,9 @@ fn session_appearing_after_startup_is_preserved_before_autosave() {
     let data_dir = config_home.join(app_dir_name());
     let herdr = spawn_herdr(&config_home, &runtime_dir, &socket_path);
     wait_for_socket(&socket_path, Duration::from_secs(5));
+    // The API socket binds before restore; a read-only App request waits for it.
+    let ready = run_cli_json(&socket_path, &["workspace", "list"]);
+    assert_eq!(ready["result"]["workspaces"], serde_json::json!([]));
     // The server has already evaluated restore, but has not created any layout.
     let original = include_bytes!("../fixtures/session/current-herdr-session.json");
     fs::write(data_dir.join("session.json"), original).unwrap();