Add pokemon evolution support across the full stack

- Evolution model with trigger, level, item, and condition fields
- Encounter.current_pokemon_id tracks evolved species separately
- Alembic migration for evolutions table and current_pokemon_id column
- Seed pipeline loads evolution data with manual overrides
- GET /pokemon/{id}/evolutions and PATCH /encounters/{id} endpoints
- Evolve button in StatusChangeModal with evolution method details
- PokemonCard shows evolved species with "Originally" label

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

backend/src/app/seeds/run.py

@@ -12,6 +12,7 @@ from app.models.pokemon import Pokemon
 from app.models.route import Route
 from app.models.route_encounter import RouteEncounter
 from app.seeds.loader import (
+    upsert_evolutions,
     upsert_games,
     upsert_pokemon,
     upsert_route_encounters,
@@ -75,6 +76,15 @@ async def seed():
             print(f"\nTotal routes: {total_routes}")
             print(f"Total encounters: {total_encounters}")
 
+            # 4. Upsert evolutions
+            evolutions_path = DATA_DIR / "evolutions.json"
+            if evolutions_path.exists():
+                evolutions_data = load_json("evolutions.json")
+                evo_count = await upsert_evolutions(session, evolutions_data, dex_to_id)
+                print(f"Evolutions: {evo_count} upserted")
+            else:
+                print("No evolutions.json found, skipping evolutions")
+
     print("Seed complete!")