refactor: use permission system instead of direct session checks in admin pages

src/app/admin/tournaments/[id]/page.tsx

@@ -2,7 +2,7 @@ import { prisma } from "@/lib/prisma"
 import Navigation from "@/components/Navigation"
 import Link from "next/link"
 import { notFound, redirect } from "next/navigation"
-import { getSession } from "@/lib/auth-simple"
+import { canManageTournament, hasRole } from "@/lib/permissions"
 import { getTournamentStatus } from "@/lib/tournamentUtils"
 
 interface PageProps {
@@ -12,21 +12,16 @@ interface PageProps {
 }
 
 export default async function TournamentDetailPage({ params }: PageProps) {
-  const session = await getSession()
-
-  if (!session) {
+  const tournamentId = parseInt(params.id)
+  
+  // Check if user can manage this tournament
+  const permission = await canManageTournament(tournamentId)
+  if (!permission.allowed) {
     redirect("/auth/login")
   }
 
-  // Fetch user role from database
-  const user = await prisma.user.findUnique({
-    where: { id: session.user.id },
-    select: { role: true },
-  });
-
-  const isAdmin = user?.role === "club_admin"
-
-  const tournamentId = parseInt(params.id)
+  // Check if user can create tournaments (tournament_admin or club_admin)
+  const canCreate = await hasRole('tournament_admin')
 
   let tournament = await prisma.event.findUnique({
     where: { id: tournamentId },
@@ -158,7 +153,7 @@ export default async function TournamentDetailPage({ params }: PageProps) {
                 )}
               </div>
               <div className="flex space-x-2">
-                {isAdmin && (
+                {permission.allowed && (
                   <>
                     <Link
                       href={`/admin/tournaments/${tournament.id}/edit`}