Move Sign Out button to profile page

- Remove Sign Out button from UserProfile component in header
- Add Sign Out button to UserProfilePage next to Edit Profile
- Sign Out button only visible on user's own profile page
- Styled with red background to indicate destructive action

src/pages/UserProfilePage.tsx

@@ -1,6 +1,7 @@
 import { useState, useEffect } from 'react';
 import { useParams, useNavigate } from 'react-router-dom';
 import { useAuth } from '@/hooks/useAuth';
+import { useClerk } from '@clerk/clerk-react';
 import { userService, type UserProfile, type UserActivity } from '@/services/userService';
 import type { Report, CleanupEvent } from '@/types';
 import { MapContainer, TileLayer, Marker, Popup } from 'react-leaflet';
@@ -23,6 +24,7 @@ L.Icon.Default.mergeOptions({
 export function UserProfilePage() {
   const { userId } = useParams<{ userId: string }>();
   const { user: currentUser } = useAuth();
+  const { signOut } = useClerk();
   const navigate = useNavigate();
   
   const [profile, setProfile] = useState<UserProfile | null>(null);
@@ -264,12 +266,23 @@ export function UserProfilePage() {
                     </button>
                   </>
                 ) : (
-                  <button
-                    onClick={handleEditProfile}
-                    className="px-4 py-2 bg-blue-600 text-white rounded-md hover:bg-blue-700"
-                  >
-                    Edit Profile
-                  </button>
+                  <>
+                    <button
+                      onClick={handleEditProfile}
+                      className="px-4 py-2 bg-blue-600 text-white rounded-md hover:bg-blue-700"
+                    >
+                      Edit Profile
+                    </button>
+                    <button
+                      onClick={async () => {
+                        await signOut();
+                        navigate('/');
+                      }}
+                      className="px-4 py-2 bg-red-600 text-white rounded-md hover:bg-red-700"
+                    >
+                      Sign Out
+                    </button>
+                  </>
                 )}
               </div>
             )}