chore: remove rendundant xTaskCreate (#1264)

## Summary

Ref discussion:
https://github.com/crosspoint-reader/crosspoint-reader/pull/1222#discussion_r2865402110

Important note that this is a bug-for-bug fix. In reality, this branch
`WiFi.status() == WL_CONNECTED` is pretty much a dead code because the
entry point of these 2 activities don't use wifi.

It is better to refactor the management of network though, but it's
better to be a dedicated PR.

---

### AI Usage

While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.

Did you use AI tools to help write this code? **NO**

src/activities/reader/KOReaderSyncActivity.cpp

@@ -204,25 +204,7 @@ void KOReaderSyncActivity::onEnter() {
   // Check if already connected (e.g. from settings page auth)
   if (WiFi.status() == WL_CONNECTED) {
     LOG_DBG("KOSync", "Already connected to WiFi");
-    state = SYNCING;
-    statusMessage = tr(STR_SYNCING_TIME);
-    requestUpdate(true);
-
-    // Perform sync directly (will be handled in loop)
-    xTaskCreate(
-        [](void* param) {
-          auto* self = static_cast<KOReaderSyncActivity*>(param);
-          // Sync time first
-          syncTimeWithNTP();
-          {
-            RenderLock lock(*self);
-            self->statusMessage = tr(STR_CALC_HASH);
-          }
-          self->requestUpdate(true);
-          self->performSync();
-          vTaskDelete(nullptr);
-        },
-        "SyncTask", 4096, this, 1, nullptr);
+    onWifiSelectionComplete(true);
     return;
   }