Demo baseline reset: full DB snapshot/restore (v2.3.0)

Hourly reset now restores entire DB from baseline snapshot instead of
just deleting demo trips. This reverts ALL demo user changes including
modifications to shared admin trips. Admin credentials (password, API
keys) are preserved across resets. Admin can save new baseline via
Admin Panel button. Removed demoWriteBlock middleware.

client/src/api/client.js

@@ -122,6 +122,7 @@ export const adminApi = {
   updateUser: (id, data) => apiClient.put(`/admin/users/${id}`, data).then(r => r.data),
   deleteUser: (id) => apiClient.delete(`/admin/users/${id}`).then(r => r.data),
   stats: () => apiClient.get('/admin/stats').then(r => r.data),
+  saveDemoBaseline: () => apiClient.post('/admin/save-demo-baseline').then(r => r.data),
 }
 
 export const mapsApi = {

client/src/pages/AdminPage.jsx

@@ -12,6 +12,7 @@ import { Users, Map, Briefcase, Shield, Trash2, Edit2, Camera, FileText, Eye, Ey
 import CustomSelect from '../components/shared/CustomSelect'
 
 export default function AdminPage() {
+  const { demoMode } = useAuthStore()
   const { t } = useTranslation()
   const TABS = [
     { id: 'users', label: t('admin.tabs.users') },
@@ -208,6 +209,29 @@ export default function AdminPage() {
             </div>
           </div>
 
+          {/* Demo Baseline Button */}
+          {demoMode && (
+            <div className="mb-6 p-4 bg-amber-50 border border-amber-200 rounded-xl flex items-center justify-between">
+              <div>
+                <p className="text-sm font-semibold text-amber-900">Demo Baseline</p>
+                <p className="text-xs text-amber-700">Save current state as the hourly reset point. All admin trips and settings will be preserved.</p>
+              </div>
+              <button
+                onClick={async () => {
+                  try {
+                    await adminApi.saveDemoBaseline()
+                    toast.success('Baseline saved! Resets will restore to this state.')
+                  } catch (e) {
+                    toast.error(e.response?.data?.error || 'Failed to save baseline')
+                  }
+                }}
+                className="px-4 py-2 bg-amber-600 text-white rounded-lg text-sm font-semibold hover:bg-amber-700 transition-colors flex-shrink-0 ml-4"
+              >
+                Save Baseline
+              </button>
+            </div>
+          )}
+
           {/* Stats */}
           {stats && (
             <div className="grid grid-cols-2 sm:grid-cols-5 gap-4 mb-6">