Arrows keep the shooter's horizontal motion on the ground, as vanilla

Projectile.shootFromRotation adds the shooter's known movement and drops
only its y on the ground, and sets no rotation after it: an arrow shot
while strafing drifts with the player in vanilla too.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

crates/horizon-client/src/game.rs

@@ -12865,14 +12865,7 @@ impl Game<'_> {
             a.ignite_for_seconds(seconds);
         }
         let (velocity, on_ground) = self.player.as_ref().map_or((Vec3::ZERO, true), |pl| {
-            (
-                if pl.ground.on_ground {
-                    Vec3::ZERO
-                } else {
-                    self.known_player_movement()
-                },
-                pl.ground.on_ground,
-            )
+            (self.known_player_movement(), pl.ground.on_ground)
         });
         arrow.shoot_from_rotation(
             &mut self.world.random,

crates/horizon-client/src/projectiles.rs

@@ -470,7 +470,6 @@ impl Projectile {
                 },
             self.velocity.z + source_velocity.z,
         );
-        self.update_rotation();
     }
     /// AbstractHurtingProjectile: movement along the direction at the acceleration power.
     pub fn fireball(