Fix message order and cursor movement

cove-tui/src/store.rs

@@ -1,13 +1,14 @@
 pub mod dummy;
 
 use std::collections::HashMap;
+use std::fmt::Debug;
 use std::hash::Hash;
 
 use async_trait::async_trait;
 use chrono::{DateTime, Utc};
 
 pub trait Msg {
-    type Id: Clone + Hash + Eq;
+    type Id: Clone + Debug + Hash + Eq + Ord;
     fn id(&self) -> Self::Id;
     fn parent(&self) -> Option<Self::Id>;
 
@@ -63,6 +64,10 @@ impl<M: Msg> Tree<M> {
             }
         }
 
+        for list in children.values_mut() {
+            list.sort_unstable();
+        }
+
         Self {
             root,
             msgs,