Enforce Dupes Clause and Shiny Clause rules

Dupes Clause greys out Pokemon in the encounter modal whose evolution
family has already been caught, preventing duplicate selections. Shiny
Clause adds a dedicated Shiny Box and lets shiny catches bypass the
one-per-route lock via a new is_shiny column on encounters and a
/pokemon/families endpoint that computes evolution family groups.

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

frontend/src/hooks/usePokemon.ts

@@ -1,5 +1,5 @@
 import { useQuery } from '@tanstack/react-query'
-import { getPokemon } from '../api/pokemon'
+import { getPokemon, fetchPokemonFamilies } from '../api/pokemon'
 
 export function usePokemon(id: number | null) {
   return useQuery({
@@ -8,3 +8,11 @@ export function usePokemon(id: number | null) {
     enabled: id !== null,
   })
 }
+
+export function usePokemonFamilies() {
+  return useQuery({
+    queryKey: ['pokemon', 'families'],
+    queryFn: fetchPokemonFamilies,
+    staleTime: Infinity,
+  })
+}