Give an endermite its own goal list

Endermite.registerGoals is the silverfish-style monster list: powder-snow climbing, a
melee attack, a stroll at 1.0, and a HurtByTargetGoal that alerts the others. Horizon
never put the endermite in the hostile family, so it fell back to the generic monster
block: stroll at 0.8, no powder-snow climb, and a hurt-by-target goal that never alerts.

crates/horizon-client/src/mobs/ai.rs

@@ -193,7 +193,7 @@ pub fn family(s: Species) -> Family {
         | S::Parched
         | S::WitherSkeleton
         | S::ZombifiedPiglin => Family::Undead,
-        S::Creeper | S::Spider | S::CaveSpider | S::Silverfish => Family::Hostile,
+        S::Creeper | S::Spider | S::CaveSpider | S::Silverfish | S::Endermite => Family::Hostile,
         S::Squid
         | S::GlowSquid
         | S::Cod
@@ -3122,6 +3122,37 @@ mod forgiveness_tests {
     }
 }
 
+#[cfg(test)]
+mod endermite_goal_tests {
+    use super::*;
+    use crate::mobs::world::with_test_world;
+
+    /// `Endermite.registerGoals` is the silverfish's family list without the
+    /// stone tricks: a powder-snow climb, a stroll at 1.0 and a
+    /// `HurtByTargetGoal` that alerts the others. The generic monster block
+    /// an unlisted species gets has none of those (stroll 0.8, no alert).
+    #[test]
+    fn an_endermite_takes_the_hostile_goal_list() {
+        let ran = with_test_world(&[], |_, types| {
+            let m = Mob::new(
+                1,
+                std::sync::Arc::new(types.types["minecraft:endermite"].clone()),
+                Vec3::ZERO,
+                0.0,
+            );
+            assert_eq!(family(m.species()), Family::Hostile);
+            assert!(
+                m.ai.goals.has("ClimbOnTopOfPowderSnow"),
+                "ClimbOnTopOfPowderSnowGoal"
+            );
+            assert!(m.ai.goals.has("Stroll"), "WaterAvoidingRandomStrollGoal");
+            assert!(m.ai.targets.has("HurtByTarget"));
+            assert!(m.ai.targets.has("NearestTarget"));
+        });
+        let _ = ran;
+    }
+}
+
 #[cfg(test)]
 mod fox_screech_tests {
     use super::*;

crates/horizon-client/src/mobs/hostile.rs

@@ -64,6 +64,19 @@ pub fn register(m: &mut Mob) {
             m.ai.targets.add(1, HurtByTarget::new().alert());
             m.ai.targets.add(2, NearestTarget::player(true));
         }
+        // Endermite.registerGoals: the silverfish's list without the stone
+        // tricks, at vanilla's priorities (stroll 1.0, alert others on hurt).
+        S::Endermite => {
+            let g = &mut m.ai.goals;
+            g.add(1, Float);
+            g.add(1, ClimbOnTopOfPowderSnow);
+            g.add(2, MeleeAttack::new(1.0, false));
+            g.add(3, Stroll::avoiding_water(1.0));
+            g.add(7, LookAtPlayer::new(8.0));
+            g.add(8, RandomLookAround::default());
+            m.ai.targets.add(1, HurtByTarget::new().alert());
+            m.ai.targets.add(2, NearestTarget::player(true));
+        }
         _ => {}
     }
 }