feat: separate regular and event entities for Pokemon and Habitats

Add dedicated routes and navigation for Event Pokemon and Event Habitats
Update API endpoints to filter by isEventItem and adapt frontend views

backend/src/server.ts

@@ -1549,7 +1549,9 @@ app.delete('/api/pokemon/:id', async (request, reply) => {
   return deleted ? reply.code(204).send() : notFound(reply, request);
 });
 
-app.get('/api/habitats', async (request) => listHabitats(requestLocale(request)));
+app.get('/api/habitats', async (request) =>
+  listHabitats(request.query as Record<string, string | string[] | undefined>, requestLocale(request))
+);
 
 app.get('/api/habitats/:id', async (request, reply) => {
   const { id } = request.params as { id: string };