touch: Wi-Fi switched on from Home joins, not just Settings > Wi-Fi

The Home "Switches" widget, the control centre and the Settings switch all
only flip the radio preference. From cold, main.cpp then starts the driver
and joins at once, and on the T-Deck that first join does not always take;
the 10 s retry after it erases the AP and the status stays "disconnected".
Opening Settings > Wi-Fi hid this: the page scans, and a scan ends with an
apply on the running driver (disconnect without erase, then begin), which
joins.

The three switches now share wifiRadioSwitch(): after turning on, once STA
has been up for 4 s without a link (and no scan owns the radio), it asks
for that same apply once. A join that works first time is left alone. Not
on the Pager (its own ordered cold start) or the Tanmatsu (Wi-Fi on the C6).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/ui-touch/UITask.cpp

@@ -20340,6 +20340,39 @@ static bool wifiPrepareEnable(lv_obj_t* switch_to_revert = nullptr) {
   return true;
 }
 
+#if defined(ESP32)
+// The Wi-Fi switches (Home "Switches" widget, control centre, Settings > Wi-Fi). Turning
+// the radio on from cold starts the driver and joins at once in main.cpp, and that first
+// join does not always take on the S3 boards; the 10 s retry after it erases the AP and
+// stays "disconnected". The Settings > Wi-Fi page hid this: opening it scans, and a scan
+// ends with a fresh apply on the running driver, which joins. So every switch gets that
+// apply too: once STA has been up for a few seconds without a link, ask for one rejoin
+// (wifiSwitchRejoinService). The Pager has its own ordered cold start; the Tanmatsu's
+// Wi-Fi lives on its C6.
+#if !defined(TLORA_PAGER) && !defined(HAS_TANMATSU)
+static uint32_t s_wifi_switch_rejoin_ms = 0;   // when the wait started; 0 = nothing pending
+static const uint32_t WIFI_SWITCH_REJOIN_MS = 4000;
+static void wifiSwitchRejoinService() {
+  if (!s_wifi_switch_rejoin_ms) return;
+  if (!wifiConfigWantsWifi() || !wifiConfigHasRuntime() || WiFi.status() == WL_CONNECTED) {
+    s_wifi_switch_rejoin_ms = 0;   // switched off again, nothing to join, or it joined
+  } else if (WiFi.getMode() == WIFI_MODE_NULL || wifiScanIsActive()) {
+    s_wifi_switch_rejoin_ms = millis();   // the driver is not up yet, or a scan owns it
+  } else if ((uint32_t)(millis() - s_wifi_switch_rejoin_ms) >= WIFI_SWITCH_REJOIN_MS) {
+    s_wifi_switch_rejoin_ms = 0;
+    Serial.println("[wifi] switched on, not joined: rejoining on the running driver");
+    wifiConfigRequestApply();   // main.cpp: disconnect(false, false) + begin, as after a scan
+  }
+}
+#endif
+static void wifiRadioSwitch(bool on) {
+  wifiConfigSetRadioEnabled(on);
+#if !defined(TLORA_PAGER) && !defined(HAS_TANMATSU)
+  s_wifi_switch_rejoin_ms = on ? millis() : 0;
+#endif
+}
+#endif
+
 // "Scan" button -> open the popup + queue a scan on the core-0 worker. If Wi-Fi
 // is off, prepare the radio first, then let the main loop initialize it before
 // the worker lists networks.
@@ -20387,6 +20420,9 @@ static void wifiKickScan() {
 // never eraseap, which wedges this radio). Drop the link, let the disassoc settle,
 // then kick the worker; wifiScanService rejoins once results land.
 static void wifiScanMainService() {
+#if !defined(TLORA_PAGER)
+  wifiSwitchRejoinService();
+#endif
   if (s_wifiscan_drop_req) {
     s_wifiscan_drop_req = false;
     if (WiFi.status() == WL_CONNECTED) {
@@ -20509,7 +20545,7 @@ static void wifiRadioToggleCb(lv_event_t* e) {
 #if defined(ESP32) && defined(MULTI_TRANSPORT_COMPANION)
   const bool on = lv_obj_has_state(lv_event_get_target(e), LV_STATE_CHECKED);
   if (on && !wifiPrepareEnable(lv_event_get_target(e))) return;
-  wifiConfigSetRadioEnabled(on);
+  wifiRadioSwitch(on);
   if (g_lv.task) g_lv.task->showAlert(on ? TR("Wi-Fi on") : TR("Wi-Fi off"), 800);
   refreshStatusLabels();
 #endif
@@ -53256,7 +53292,7 @@ static void ccWifiCb(lv_event_t* e) {
   // releases NimBLE so Wi-Fi can claim its allocation first.
   const bool on = wifiConfigGetRadioEnabled();
   if (!on && !wifiPrepareEnable()) { openControlCenter(); return; }
-  wifiConfigSetRadioEnabled(!on);
+  wifiRadioSwitch(!on);
   if (g_lv.task) g_lv.task->showAlert(on ? TR("Wi-Fi off") : TR("Wi-Fi on"), 800);
   openControlCenter();
 #endif
@@ -62158,7 +62194,7 @@ static void hwToggleFlip(uint8_t id) {
     case HWT_WIFI: {
       const bool on = wifiConfigGetRadioEnabled();
       if (!on && !wifiPrepareEnable()) return;
-      wifiConfigSetRadioEnabled(!on);
+      wifiRadioSwitch(!on);   // the same path as the Settings switch, rejoin included
       break;
     }
     case HWT_BT: