Drop the hand after placing or using an item on a server

The server-client use path never called LocalPlayer.itemUsed, so the held item stayed up after a placement. Vanilla drops it after a swinging useItemOn that spent the item (or in creative) and after every successful useItem.

crates/horizon-client/src/game/remote.rs

@@ -4627,9 +4627,26 @@ impl Game<'_> {
         false
     }
 
+    /// `Minecraft.startUseItem`'s block turn for `hand`: a use that swung drops
+    /// the hand (`LocalPlayer.itemUsed`) when it spent the held item or the
+    /// player has infinite materials.
+    fn remote_use_block(&mut self, hand: Hand) -> bool {
+        let before = self.with_hand(hand, |g| g.held().map(|s| s.count));
+        let swings = self.swings_started;
+        let done = self.remote_use_item_on(hand);
+        if done
+            && self.swings_started != swings
+            && let Some(after) = self.with_hand(hand, |g| g.held().map(|s| s.count))
+            && (Some(after) != before || self.creative)
+        {
+            self.heights.item_used(hand);
+        }
+        done
+    }
+
     /// MultiPlayerGameMode.useItemOn for `hand`: whether the click ends there
     /// (the block reacts, or a block item is placed).
-    fn remote_use_block(&mut self, hand: Hand) -> bool {
+    fn remote_use_item_on(&mut self, hand: Hand) -> bool {
         let held = self.with_hand(hand, |g| g.held().cloned());
         let held_block = held
             .as_ref()
@@ -5003,7 +5020,9 @@ impl Game<'_> {
     /// the main hand's item, then the off hand's turn (its block, its item).
     /// The server does each packet's part with that packet's hand only.
     fn remote_use_hands(&mut self) {
+        // A successful Item.use always drops the hand (LocalPlayer.itemUsed).
         if self.remote_use_item(Hand::Main) {
+            self.heights.item_used(Hand::Main);
             return;
         }
         // The off hand's turn: the entity again, or the block.
@@ -5015,7 +5034,9 @@ impl Game<'_> {
         if off_target {
             return;
         }
-        self.remote_use_item(Hand::Off);
+        if self.remote_use_item(Hand::Off) {
+            self.heights.item_used(Hand::Off);
+        }
     }
     /// `LivingEntity.updatingUsingItem` on a server client: an item held in
     /// use (`held_until_released`), and a consumable's eating animation and