fix: single boot refresh with QR code, async WiFi scan, skip light sleep in AP mode

Co-authored-by: Cursor <cursoragent@cursor.com>

data/setup.html

@@ -46,13 +46,24 @@
         async function scanNetworks() {
             try {
                 const res = await fetch('/api/wifi/scan');
-                const networks = await res.json();
+                const data = await res.json();
+                if (data.scanning) {
+                    // Scan in progress — retry after 2s
+                    setTimeout(scanNetworks, 2000);
+                    return;
+                }
                 const select = document.getElementById('wifiSsid');
-                select.innerHTML = networks.map(n =>
+                if (data.length === 0) {
+                    select.innerHTML = '<option value="">No networks found</option>';
+                    setTimeout(scanNetworks, 3000);
+                    return;
+                }
+                select.innerHTML = data.map(n =>
                     `<option value="${n.ssid}">${n.ssid} (${n.rssi}dBm)</option>`
                 ).join('');
             } catch (e) {
                 console.error('Scan failed:', e);
+                setTimeout(scanNetworks, 3000);
             }
         }