feat: update admin dashboard - remove auto-refresh and export buttons

- Remove Auto-refresh toggle from header
- Remove Export CSV button
- Keep only Rafraîchir button

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

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

app/admin/dashboard/page.tsx

@@ -210,26 +210,6 @@ export default function AdminDashboardAdvanced() {
             </div>
 
             <div className="flex flex-wrap items-center gap-3">
-              {/* Auto-refresh toggle */}
-              <label className="flex items-center gap-2 bg-white/10 backdrop-blur-sm px-4 py-2.5 rounded-xl border border-white/20 cursor-pointer hover:bg-white/20 transition-all">
-                <input
-                  type="checkbox"
-                  checked={autoRefresh}
-                  onChange={(e) => setAutoRefresh(e.target.checked)}
-                  className="rounded accent-white"
-                />
-                <span className="text-sm font-medium text-white">Auto-refresh ({refreshInterval}s)</span>
-              </label>
-
-              {/* Export button */}
-              <button
-                onClick={exportToCSV}
-                className="flex items-center gap-2 bg-emerald-500 text-white px-5 py-2.5 rounded-xl hover:bg-emerald-600 transition-all shadow-lg font-medium"
-              >
-                <Download className="w-4 h-4" />
-                Export CSV
-              </button>
-
               {/* Refresh button */}
               <button
                 onClick={loadStatistics}