test(e2e): wait for the join and the password change, not a sleep

The chat-room test gave both joins 500 ms before speaking; a line said
before bob is in the room never reaches him. It now waits until each
has the member list the server sends once they are in.

The password test slept 500 ms and then disconnected. soulfind stores a
new password only after hashing it, and drops the change if the session
closes first, so a slow hash let the old password keep working. The
session now stays up until a login with the new password is accepted.

soulseek-rs-lib/tests/e2e.rs

@@ -327,8 +327,15 @@ fn a_chat_room_message_is_delivered_between_users() {
     alice.join_room(room).expect("alice joins room");
     bob.join_room(room).expect("bob joins room");
 
-    // Give both joins time to register on the server before speaking.
-    std::thread::sleep(Duration::from_millis(500));
+    // Each is in once the server has sent them the member list; a line said
+    // before bob is in never reaches him.
+    let deadline = Instant::now() + Duration::from_secs(5);
+    while alice.room_members(room).is_empty()
+        || bob.room_members(room).is_empty()
+    {
+        assert!(Instant::now() < deadline, "both should get into the room");
+        std::thread::sleep(Duration::from_millis(50));
+    }
     let _ = alice.take_room_events();
     let _ = bob.take_room_events();
 
@@ -4256,7 +4263,23 @@ fn a_changed_password_is_what_the_next_login_needs() {
     client
         .change_password("second-pw")
         .expect("change password");
-    std::thread::sleep(Duration::from_millis(500));
+    // soulfind stores the new password once it has hashed it, and forgets the
+    // change if our session closes first. The session stays until a login
+    // with the new password shows it landed; a refused one leaves it alone.
+    let deadline = Instant::now() + Duration::from_secs(10);
+    loop {
+        let mut fresh =
+            Client::with_settings(server.settings(user, "second-pw"));
+        fresh.connect().expect("connect with the new password");
+        if matches!(fresh.login(), Ok(true)) {
+            break;
+        }
+        assert!(
+            Instant::now() < deadline,
+            "the new password must be accepted"
+        );
+        std::thread::sleep(Duration::from_millis(100));
+    }
     drop(client);
 
     let mut stale = Client::with_settings(server.settings(user, "first-pw"));
@@ -4265,14 +4288,6 @@ fn a_changed_password_is_what_the_next_login_needs() {
         !matches!(stale.login(), Ok(true)),
         "the old password must stop working"
     );
-    drop(stale);
-
-    let mut fresh = Client::with_settings(server.settings(user, "second-pw"));
-    fresh.connect().expect("connect with the new password");
-    assert!(
-        fresh.login().expect("login with the new password"),
-        "the new password must be accepted"
-    );
 }
 
 #[test]