feat: add TypeScript definitions for next-auth session with accessToken and user details

_archive/frontend/lib/auth-headers.ts

@@ -0,0 +1,24 @@
+import { auth } from '../auth';
+
+/**
+ * Returnerar Authorization-header med JWT från sessionen.
+ * Används i alla server-side API-proxy-routes.
+ */
+export async function getAuthHeaders(): Promise<Record<string, string>> {
+  const session = await auth();
+  // eslint-disable-next-line no-console
+  console.log('[getAuthHeaders] Session data:', {
+    hasSession: !!session,
+    hasAccessToken: !!session?.accessToken,
+    sessionKeys: session ? Object.keys(session) : [],
+    userRole: (session?.user as any)?.role,
+  });
+  if (!session?.accessToken) {
+    // eslint-disable-next-line no-console
+    console.warn('[getAuthHeaders] No accessToken found! Session:', session);
+    return {};
+  }
+  // eslint-disable-next-line no-console
+  console.log('[getAuthHeaders] Returning Bearer token');
+  return { Authorization: `Bearer ${session.accessToken}` };
+}