WiFi screen: reach the root helper through a socket instead of sudo; adapter dropdown

The kiosk app can end up with the no-new-privileges flag, after which sudo
refuses to run ("The no new privileges flag is set"). The helper is now
served over a root-owned, kiosk-group-only unix socket (systemd socket
activation); sudo stays as a fallback. With several WiFi adapters the screen
shows a dropdown and lists all of them; status/scan/connect take an iface.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013wi3ZQveYdjfcrEsyazq32

kiosk-app/wifi.html

@@ -95,7 +95,11 @@
   </div>
 
   <div id="wifi-step" class="hidden">
-    <div id="status">Checking…</div>
+    <div id="adapter-row" class="hidden">
+      <label for="adapter" style="margin-top: 0">WiFi adapter</label>
+      <select id="adapter"></select>
+    </div>
+    <div id="status" style="margin-top: 12px">Checking…</div>
 
     <div class="row" style="margin-top: 14px">
       <label style="margin: 0; flex: 1">Networks nearby</label>
@@ -139,6 +143,7 @@
     const {ipcRenderer} = require('electron');
     const $ = id => document.getElementById(id);
     let busy = false;
+    let adapter = '';   // the adapter picked in the dropdown ('' = let the helper choose)
 
     function request(action, extra) {
       return ipcRenderer.invoke('wifi-request', Object.assign({action}, extra || {}))
@@ -163,16 +168,47 @@
       return '▂';
     }
 
+    function adapterLabel(a) {
+      const kind = a.kind === 'usb' ? 'USB' : 'built-in';
+      return `${a.name} (${kind}) - ` + (a.connected ? `connected to "${a.ssid}"` : 'not connected');
+    }
+
+    // Fill the dropdown from the helper's adapter list. Shown only when
+    // there is more than one adapter; the choice sticks across refreshes.
+    function fillAdapters(r) {
+      const row = $('adapter-row');
+      const sel = $('adapter');
+      if (!r || !r.ok || !r.adapters || r.adapters.length === 0) { row.classList.add('hidden'); return r; }
+      const names = r.adapters.map(a => a.name);
+      if (!names.includes(adapter)) adapter = r.selected || names[0];
+      sel.textContent = '';
+      for (const a of r.adapters) {
+        const o = document.createElement('option');
+        o.value = a.name;
+        o.textContent = adapterLabel(a);
+        if (a.name === adapter) o.selected = true;
+        sel.appendChild(o);
+      }
+      row.classList.toggle('hidden', r.adapters.length < 2);
+      return r;
+    }
+
     async function refreshStatus() {
-      const s = await request('status');
+      const ad = fillAdapters(await request('ifaces'));
+      const s = await request('status', adapter ? {iface: adapter} : {});
       const box = $('status');
       if (!s.ok) { box.textContent = s.error || 'Status unavailable'; return; }
       if (!s.iface) { box.textContent = 'No WiFi adapter found'; return; }
       box.textContent = '';
       const line = (text) => { const d = document.createElement('div'); d.textContent = text; box.appendChild(d); };
-      line(s.connected ? `Connected to "${s.ssid}" - ${s.ip}` : 'Not connected');
+      if (ad && ad.ok && ad.adapters && ad.adapters.length > 1) {
+        // Every adapter at a glance, the selected one marked.
+        for (const a of ad.adapters) line((a.name === s.iface ? '▶ ' : '   ') + adapterLabel(a) + (a.ip ? ` - ${a.ip}` : ''));
+      } else {
+        line(s.connected ? `Connected to "${s.ssid}" - ${s.ip}` : 'Not connected');
+        line(`Adapter: ${s.iface}`);
+      }
       if (s.configured && s.configured !== s.ssid) line(`Saved network: "${s.configured}"`);
-      line(`Adapter: ${s.iface}`);
       if (!$('ssid').value && (s.ssid || s.configured)) $('ssid').value = s.ssid || s.configured;
     }
 
@@ -181,7 +217,7 @@
       setBusy(true);
       message('Scanning…', 'busy');
       const list = $('networks');
-      const r = await request('scan');
+      const r = await request('scan', adapter ? {iface: adapter} : {});
       list.textContent = '';
       if (!r.ok) {
         message(r.error, 'error');
@@ -217,7 +253,7 @@
       if (!ssid) { message('Pick a network or type its name', 'error'); return; }
       setBusy(true);
       message(`Connecting to "${ssid}" (up to 30 seconds)…`, 'busy');
-      const r = await request('connect', {ssid, password});
+      const r = await request('connect', {ssid, password, iface: adapter});
       if (r.ok) {
         message(`✓ Connected to "${r.ssid}" - ${r.ip}`, 'ok');
         $('password').value = '';
@@ -287,14 +323,19 @@
       message('');
       $('pin-step').classList.add('hidden');
       $('wifi-step').classList.remove('hidden');
-      refreshStatus();
+      refreshStatus().then(() => scan());
       loadRegion();
-      scan();
     }
 
     $('pin-ok').addEventListener('click', unlock);
     $('pin').addEventListener('keydown', e => { if (e.key === 'Enter') unlock(); });
     $('scan').addEventListener('click', scan);
+    $('adapter').addEventListener('change', () => {
+      adapter = $('adapter').value;
+      $('networks').innerHTML = '<li class="empty">Scanning…</li>';
+      refreshStatus();
+      scan();
+    });
     $('region-save').addEventListener('click', saveRegion);
     $('region-from-locale').addEventListener('click', countryFromLocale);
     $('connect').addEventListener('click', connect);