añadido componente para crear posts y modificado menu auth

src/lib/stores/usuario.ts

@@ -1,7 +1,16 @@
 import { writable } from 'svelte/store';
+import { browser } from '$app/environment';
 import type { Sesion } from '../../types';
 
-export const currentSesion = writable<Sesion| null>(null);
+const initialValue = browser ? JSON.parse(localStorage.getItem('sesion') || 'null') : null;
+
+export const currentSesion = writable<Sesion | null>(initialValue);
+
+if (browser) {
+	currentSesion.subscribe((value) => {
+		localStorage.setItem('sesion', JSON.stringify(value));
+	});
+}
 
 export const sesionStore = {
 	subscribe: currentSesion.subscribe,