Add Logout button to map page

Add logout functionality to map page header:
- Import signOut from next-auth/react
- Add Logout button next to Admin button
- Use same red gradient styling as admin layout
- Redirect to /login after logout

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

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

app/map/page.tsx

@@ -3,6 +3,7 @@
 import { useState, useEffect } from "react";
 import dynamic from "next/dynamic";
 import Link from "next/link";
+import { signOut } from "next-auth/react";
 
 const MapView = dynamic(() => import("@/components/map/MapView"), {
   ssr: false,
@@ -127,7 +128,7 @@ export default function MapPage() {
             {/* Spacer to push buttons to the right */}
             <div className="hidden lg:block lg:flex-1"></div>
 
-            {/* Export and Admin Buttons */}
+            {/* Export, Admin and Logout Buttons */}
             <div className="flex items-center gap-2">
               <a
                 href="/export"
@@ -142,6 +143,15 @@ export default function MapPage() {
               >
                 Admin
               </a>
+              <button
+                onClick={async () => {
+                  await signOut({ redirect: false });
+                  window.location.href = '/login';
+                }}
+                className="inline-flex items-center px-4 py-2 text-sm font-medium text-white bg-gradient-to-r from-red-600 to-red-700 border border-red-600 rounded-lg hover:from-red-700 hover:to-red-800 transition-all duration-200 shadow-md hover:shadow-lg"
+              >
+                Logout
+              </button>
             </div>
           </div>