SSH reconnect reliability (#19398)

Release Notes:

- SSH Remoting: Fix message reliability across restarts

---------

Co-authored-by: Nathan <nathan@zed.dev>

crates/remote_server/src/remote_editing_tests.rs

@@ -641,6 +641,47 @@ async fn test_open_server_settings(cx: &mut TestAppContext, server_cx: &mut Test
     })
 }
 
+#[gpui::test(iterations = 10)]
+async fn test_reconnect(cx: &mut TestAppContext, server_cx: &mut TestAppContext) {
+    let (project, _headless, fs) = init_test(cx, server_cx).await;
+
+    let (worktree, _) = project
+        .update(cx, |project, cx| {
+            project.find_or_create_worktree("/code/project1", true, cx)
+        })
+        .await
+        .unwrap();
+
+    let worktree_id = worktree.read_with(cx, |worktree, _| worktree.id());
+    let buffer = project
+        .update(cx, |project, cx| {
+            project.open_buffer((worktree_id, Path::new("src/lib.rs")), cx)
+        })
+        .await
+        .unwrap();
+
+    buffer.update(cx, |buffer, cx| {
+        assert_eq!(buffer.text(), "fn one() -> usize { 1 }");
+        let ix = buffer.text().find('1').unwrap();
+        buffer.edit([(ix..ix + 1, "100")], None, cx);
+    });
+
+    let client = cx.read(|cx| project.read(cx).ssh_client().unwrap());
+    client
+        .update(cx, |client, cx| client.simulate_disconnect(cx))
+        .detach();
+
+    project
+        .update(cx, |project, cx| project.save_buffer(buffer.clone(), cx))
+        .await
+        .unwrap();
+
+    assert_eq!(
+        fs.load("/code/project1/src/lib.rs".as_ref()).await.unwrap(),
+        "fn one() -> usize { 100 }"
+    );
+}
+
 fn init_logger() {
     if std::env::var("RUST_LOG").is_ok() {
         env_logger::try_init().ok();
@@ -651,9 +692,9 @@ async fn init_test(
     cx: &mut TestAppContext,
     server_cx: &mut TestAppContext,
 ) -> (Model<Project>, Model<HeadlessProject>, Arc<FakeFs>) {
-    let (ssh_remote_client, ssh_server_client) = SshRemoteClient::fake(cx, server_cx);
     init_logger();
 
+    let (forwarder, ssh_server_client) = SshRemoteClient::fake_server(server_cx);
     let fs = FakeFs::new(server_cx.executor());
     fs.insert_tree(
         "/code",
@@ -694,8 +735,9 @@ async fn init_test(
             cx,
         )
     });
-    let project = build_project(ssh_remote_client, cx);
 
+    let ssh = SshRemoteClient::fake_client(forwarder, cx).await;
+    let project = build_project(ssh, cx);
     project
         .update(cx, {
             let headless = headless.clone();