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/rezepte/add/+page.server.ts

@@ -1,5 +1,6 @@
 export async function load({locals}) {
+    const session = await locals.auth();
     return {
-	user: locals.user
+	user: session?.user
     };
 };