feat(pet): add Hey Hey chicken pet addon

Tameable white chicken modelled on Hey Hey from Moana — custom plump
geometry, waddly walk/peck animations, hatching egg item, and vanilla
chicken sounds. Mounted on all 4 servers via docker-compose.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

addon/heyhe_pet_BP/recipes/heyhe_egg.json

@@ -0,0 +1,18 @@
+{
+  "format_version": "1.21.0",
+  "minecraft:recipe_shapeless": {
+    "description": {
+      "identifier": "silverlabs:heyhe_egg_recipe"
+    },
+    "tags": ["crafting_table"],
+    "ingredients": [
+      { "item": "minecraft:egg" },
+      { "item": "minecraft:feather" },
+      { "item": "minecraft:gold_nugget" }
+    ],
+    "result": {
+      "item": "silverlabs:heyhe_egg",
+      "count": 1
+    }
+  }
+}