Update @auth/sveltekit to latest stable version 1.10.0

- Upgraded @auth/sveltekit from 0.14.0 to 1.10.0
- Updated session API from event.locals.getSession() to event.locals.auth()
- Fixed TypeScript definitions for new auth API in app.d.ts
- Updated layout server load functions to use LayoutServerLoad type
- Fixed session callbacks with proper token type casting
- Switched to generic OIDC provider config to resolve issuer validation issues
- All auth functionality now working with latest Auth.js version

🤖 Generated with [Claude Code](https://claude.ai/code)

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

src/routes/(main)/+layout.server.ts

@@ -1,6 +1,6 @@
-import type { PageServerLoad } from "./$types"
+import type { LayoutServerLoad } from "./$types"
 
-export const load : PageServerLoad = (async ({locals}) => {
+export const load : LayoutServerLoad = (async ({locals}) => {
 	return {
 		session: await locals.auth(),
 	}