feat(spark_pet): major overhaul — traits, animations, riding, fire, coloured hatching

- Movement: slower follow (speed 0.3, stop_dist 5), near-zero teleport chance
- Scales: baby 0.65, juvenile 0.9, adult 1.3 (up from 0.4/0.7/1.0)
- Personality traits (0–4): set by feeding specific foods while sneaking;
  affects stroll range, follow distance, look-at-player frequency
- Passtime animations driven by pure Molang lifecycle math (no timer components):
  groom, sniff, stretch, happy_bounce cycling ~every 3 min per dragon
- Rideable adults: minecraft:rideable + input_ground_controlled, seat at [0,0.9,-0.3]
- Fire breathing: autonomous vs monsters (radius 16) + player-triggered (sneak + fire_charge)
- New hatching system: 6 nest block variants (oak/spruce/jungle/crimson/warped/obsidian),
  craft nest + dragon_egg → coloured egg item; place egg, bonemeal + blaze powder → hatch;
  dragon colour matches nest type via 6 separate egg entity types + born_color events
- 18 new PNG textures: 6 dragon colours, 6 nest blocks, 6 egg items (HSV hue rotation)
- Render controller updated to use texture array indexed by silverlabs:dragon_color property

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

addon/spark_pet_BP/blocks/dragon_nest_oak.json

@@ -0,0 +1,20 @@
+{
+  "format_version": "1.21.0",
+  "minecraft:block": {
+    "description": {
+      "identifier": "silverlabs:dragon_nest_oak",
+      "menu_category": { "category": "items", "group": "itemGroup.name.bed" }
+    },
+    "components": {
+      "minecraft:geometry": "geometry.dragon_basket",
+      "minecraft:material_instances": {
+        "*": { "texture": "dragon_nest_oak", "render_method": "alpha_test" }
+      },
+      "minecraft:collision_box": { "origin": [-7, 0, -7], "size": [14, 5, 14] },
+      "minecraft:selection_box": { "origin": [-7, 0, -7], "size": [14, 5, 14] },
+      "minecraft:destructible_by_mining": { "seconds_to_destroy": 1.0 },
+      "minecraft:destructible_by_explosion": { "explosion_resistance": 2.0 },
+      "minecraft:map_color": "#C8A87A"
+    }
+  }
+}