Update seed data and boss sprites from latest export

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

backend/src/app/seeds/data/omega-ruby-bosses.json

@@ -0,0 +1,16 @@
+[
+  {
+    "name": "Wattson",
+    "boss_type": "gym_leader",
+    "specialty_type": "electric",
+    "badge_name": "Dynamo Badge",
+    "badge_image_url": "/badges/dynamo-badge.png",
+    "level_cap": 15,
+    "order": 1,
+    "after_route_name": "Rustboro City",
+    "location": "Mauville Gym",
+    "section": "Main Story",
+    "sprite_url": "/boss-sprites/omega-ruby/wattson.png",
+    "pokemon": []
+  }
+]