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/components/PokemonCard.tsx

@@ -28,8 +28,10 @@ const typeColors: Record<string, string> = {
 }
 
 export function PokemonCard({ encounter, showFaintLevel, onClick }: PokemonCardProps) {
-  const { pokemon, route, nickname, catchLevel, faintLevel, deathCause } = encounter
+  const { pokemon, currentPokemon, route, nickname, catchLevel, faintLevel, deathCause } = encounter
   const isDead = faintLevel !== null
+  const displayPokemon = currentPokemon ?? pokemon
+  const isEvolved = currentPokemon !== null
 
   return (
     <div
@@ -38,15 +40,15 @@ export function PokemonCard({ encounter, showFaintLevel, onClick }: PokemonCardP
         isDead ? 'opacity-60 grayscale' : ''
       } ${onClick ? 'cursor-pointer hover:ring-2 hover:ring-blue-400 transition-shadow' : ''}`}
     >
-      {pokemon.spriteUrl ? (
+      {displayPokemon.spriteUrl ? (
         <img
-          src={pokemon.spriteUrl}
-          alt={pokemon.name}
+          src={displayPokemon.spriteUrl}
+          alt={displayPokemon.name}
           className="w-16 h-16"
         />
       ) : (
         <div className="w-16 h-16 rounded-full bg-gray-300 dark:bg-gray-600 flex items-center justify-center text-xl font-bold text-gray-600 dark:text-gray-300">
-          {pokemon.name[0].toUpperCase()}
+          {displayPokemon.name[0].toUpperCase()}
         </div>
       )}
 
@@ -55,17 +57,17 @@ export function PokemonCard({ encounter, showFaintLevel, onClick }: PokemonCardP
           className={`w-2 h-2 rounded-full shrink-0 ${isDead ? 'bg-red-500' : 'bg-green-500'}`}
         />
         <span className="font-semibold text-gray-900 dark:text-gray-100 text-sm">
-          {nickname || pokemon.name}
+          {nickname || displayPokemon.name}
         </span>
       </div>
       {nickname && (
         <div className="text-xs text-gray-500 dark:text-gray-400">
-          {pokemon.name}
+          {displayPokemon.name}
         </div>
       )}
 
       <div className="flex gap-1 mt-1">
-        {pokemon.types.map((type) => (
+        {displayPokemon.types.map((type) => (
           <span
             key={type}
             className={`px-1.5 py-0.5 rounded text-[10px] font-medium text-white ${typeColors[type] ?? 'bg-gray-500'}`}
@@ -85,6 +87,12 @@ export function PokemonCard({ encounter, showFaintLevel, onClick }: PokemonCardP
         {route.name}
       </div>
 
+      {isEvolved && (
+        <div className="text-[10px] text-gray-400 dark:text-gray-500 mt-0.5">
+          Originally: {pokemon.name}
+        </div>
+      )}
+
       {isDead && deathCause && (
         <div className="text-[10px] italic text-gray-400 dark:text-gray-500 mt-0.5 line-clamp-2">
           {deathCause}