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/schemas/__init__.py

@@ -17,6 +17,7 @@ from app.schemas.game import (
 from app.schemas.pokemon import (
     BulkImportItem,
     BulkImportResult,
+    EvolutionResponse,
     PokemonCreate,
     PokemonResponse,
     PokemonUpdate,
@@ -34,6 +35,7 @@ __all__ = [
     "EncounterDetailResponse",
     "EncounterResponse",
     "EncounterUpdate",
+    "EvolutionResponse",
     "GameCreate",
     "GameDetailResponse",
     "GameResponse",

backend/src/app/schemas/encounter.py

@@ -18,6 +18,7 @@ class EncounterUpdate(CamelModel):
     status: str | None = None
     faint_level: int | None = None
     death_cause: str | None = None
+    current_pokemon_id: int | None = None
 
 
 class EncounterResponse(CamelModel):
@@ -25,6 +26,7 @@ class EncounterResponse(CamelModel):
     run_id: int
     route_id: int
     pokemon_id: int
+    current_pokemon_id: int | None
     nickname: str | None
     status: str
     catch_level: int | None
@@ -35,4 +37,5 @@ class EncounterResponse(CamelModel):
 
 class EncounterDetailResponse(EncounterResponse):
     pokemon: PokemonResponse
+    current_pokemon: PokemonResponse | None
     route: RouteResponse

backend/src/app/schemas/pokemon.py

@@ -11,6 +11,17 @@ class PokemonResponse(CamelModel):
     sprite_url: str | None
 
 
+class EvolutionResponse(CamelModel):
+    id: int
+    from_pokemon_id: int
+    to_pokemon: PokemonResponse
+    trigger: str
+    min_level: int | None
+    item: str | None
+    held_item: str | None
+    condition: str | None
+
+
 class RouteEncounterResponse(CamelModel):
     id: int
     route_id: int