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/types/game.ts

@@ -44,6 +44,7 @@ export interface Encounter {
   runId: number
   routeId: number
   pokemonId: number
+  currentPokemonId: number | null
   nickname: string | null
   status: EncounterStatus
   catchLevel: number | null
@@ -71,9 +72,21 @@ export interface RunDetail extends NuzlockeRun {
 
 export interface EncounterDetail extends Encounter {
   pokemon: Pokemon
+  currentPokemon: Pokemon | null
   route: Route
 }
 
+export interface Evolution {
+  id: number
+  fromPokemonId: number
+  toPokemon: Pokemon
+  trigger: string
+  minLevel: number | null
+  item: string | null
+  heldItem: string | null
+  condition: string | null
+}
+
 export interface CreateRunInput {
   gameId: number
   name: string
@@ -99,6 +112,7 @@ export interface UpdateEncounterInput {
   status?: EncounterStatus
   faintLevel?: number
   deathCause?: string
+  currentPokemonId?: number
 }
 
 // Re-export for convenience