docs: add missing import and type decl to sveltekit tutorial (#21634)

* docs: add missing import and type decl to sveltekit tutorial

* update +layout.server.ts in sveltekit code example

* update remaining

* chore: fix formatting

---------

Co-authored-by: Charis <26616127+charislam@users.noreply.github.com>

examples/user-management/sveltekit-user-management/src/routes/+layout.server.ts

@@ -1,5 +1,7 @@
 // src/routes/+layout.server.ts
-export const load = async ({ locals: { getSession } }) => {
+import type { LayoutServerLoad } from './$types'
+
+export const load: LayoutServerLoad = async ({ locals: { getSession } }) => {
 	return {
 		session: await getSession()
 	}

examples/user-management/sveltekit-user-management/src/routes/+page.server.ts

@@ -1,7 +1,8 @@
 // src/routes/+page.server.ts
 import { redirect } from '@sveltejs/kit'
+import type { PageServerLoad } from './$types'
 
-export const load = async ({ url, locals: { getSession } }) => {
+export const load: PageServerLoad = async ({ url, locals: { getSession } }) => {
 	const session = await getSession()
 
 	// if the user is already logged in return them to the account page

examples/user-management/sveltekit-user-management/src/routes/account/+page.server.ts

@@ -1,6 +1,7 @@
 import { fail, redirect } from '@sveltejs/kit'
+import type { Actions, PageServerLoad } from './$types'
 
-export const load = async ({ locals: { supabase, getSession } }) => {
+export const load: PageServerLoad = async ({ locals: { supabase, getSession } }) => {
 	const session = await getSession()
 
 	if (!session) {
@@ -16,7 +17,7 @@ export const load = async ({ locals: { supabase, getSession } }) => {
 	return { profile }
 }
 
-export const actions = {
+export const actions: Actions = {
 	update: async ({ request, locals: { supabase, getSession } }) => {
 		const formData = await request.formData()
 		const fullName = formData.get('fullName') as string