Add genlocke cumulative graveyard with backend endpoint and UI

Aggregates all fainted encounters across every leg of a genlocke into a
unified graveyard view. Backend serves GET /genlockes/{id}/graveyard with
per-entry leg/game context and summary stats (total deaths, deaths per
leg, deadliest leg). Frontend adds a toggle button on the genlocke detail
page that reveals a filterable/sortable grid of grayscale Pokemon cards.

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

frontend/src/hooks/useGenlockes.ts

@@ -1,5 +1,5 @@
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query'
-import { advanceLeg, createGenlocke, getGamesByRegion, getGenlockes, getGenlocke } from '../api/genlockes'
+import { advanceLeg, createGenlocke, getGamesByRegion, getGenlockes, getGenlocke, getGenlockeGraveyard } from '../api/genlockes'
 import type { CreateGenlockeInput } from '../types/game'
 
 export function useGenlockes() {
@@ -16,6 +16,13 @@ export function useGenlocke(id: number) {
   })
 }
 
+export function useGenlockeGraveyard(id: number) {
+  return useQuery({
+    queryKey: ['genlockes', id, 'graveyard'],
+    queryFn: () => getGenlockeGraveyard(id),
+  })
+}
+
 export function useRegions() {
   return useQuery({
     queryKey: ['games', 'by-region'],