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>

frontend/src/hooks/useEncounters.ts

@@ -1,8 +1,9 @@
-import { useMutation, useQueryClient } from '@tanstack/react-query'
+import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query'
 import {
   createEncounter,
   updateEncounter,
   deleteEncounter,
+  fetchEvolutions,
 } from '../api/encounters'
 import type { CreateEncounterInput, UpdateEncounterInput } from '../types/game'
 
@@ -41,3 +42,11 @@ export function useDeleteEncounter(runId: number) {
     },
   })
 }
+
+export function useEvolutions(pokemonId: number | null) {
+  return useQuery({
+    queryKey: ['evolutions', pokemonId],
+    queryFn: () => fetchEvolutions(pokemonId!),
+    enabled: pokemonId !== null,
+  })
+}