Add pre-commit hooks for linting and formatting

Set up pre-commit framework with ruff (backend) and ESLint/Prettier/tsc
(frontend) hooks to catch issues locally before CI. Auto-format all
frontend files with Prettier to comply with the new check.

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

frontend/src/api/games.ts

@@ -19,7 +19,10 @@ export function getGameRoutes(gameId: number): Promise<Route[]> {
   return api.get(`/games/${gameId}/routes?flat=true`)
 }
 
-export function getRoutePokemon(routeId: number, gameId?: number): Promise<RouteEncounterDetail[]> {
+export function getRoutePokemon(
+  routeId: number,
+  gameId?: number
+): Promise<RouteEncounterDetail[]> {
   const params = gameId != null ? `?game_id=${gameId}` : ''
   return api.get(`/routes/${routeId}/pokemon${params}`)
 }