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/app.d.ts

@@ -1,12 +1,28 @@
 // See https://kit.svelte.dev/docs/types#app
 // for information about these interfaces
+import type { Session } from "@auth/sveltekit";
+
 declare global {
 	namespace App {
 		// interface Error {}
-		// interface Locals {}
+		interface Locals {
+			auth(): Promise<Session | null>;
+		}
 		// interface PageData {}
 		// interface Platform {}
 	}
 }
 
+declare module "@auth/sveltekit" {
+	interface Session {
+		user?: {
+			name?: string | null;
+			email?: string | null;
+			image?: string | null;
+			nickname?: string;
+			groups?: string[];
+		};
+	}
+}
+
 export {};