fix: move FTP task to core 1 — core 0 reserved for WiFi stack

FTP task on core 0 at priority 2 starved the WiFi networking stack,
preventing the FTP welcome banner from being sent. Moved to core 1
with 2ms yield to coexist with LVGL rendering.

src/main.cpp

@@ -449,12 +449,16 @@ static void initNtp() {
     Serial.println("[NTP] Warning: time not yet synced (will update in background)");
 }
 
-/** FTP task — runs handleFTP() in a dedicated loop on core 0 */
+/** FTP task — runs handleFTP() in a dedicated loop on core 1
+ *  NOTE: Must run on core 1 (not core 0) because WiFi runs on core 0
+ *  and handleFTP() needs WiFi sockets to work. Running on core 0 at
+ *  higher priority starves WiFi, preventing welcome banner from sending.
+ */
 static void ftpTask(void *param) {
     (void)param;
     for (;;) {
         ftpSrv.handleFTP();
-        vTaskDelay(pdMS_TO_TICKS(1));  // yield ~1 ms between iterations
+        vTaskDelay(pdMS_TO_TICKS(2));  // yield 2ms to let LVGL run
     }
 }
 
@@ -467,8 +471,9 @@ static void initFtp() {
     ftpSrv.setLocalIp(WiFi.localIP());
     ftpSrv.begin("kode", "kode");
 
-    /* Run FTP in its own task on core 0 so it never blocks LVGL on core 1 */
-    xTaskCreatePinnedToCore(ftpTask, "ftp", 32768, NULL, 2, NULL, 0);
+    /* Run FTP in its own task on core 1 (same as Arduino) — core 0 is
+       reserved for WiFi/networking stack, running FTP there starves it */
+    xTaskCreatePinnedToCore(ftpTask, "ftp", 32768, NULL, 2, NULL, 1);
 
     Serial.printf("[FTP] FTP server ready on core 0 (PASV IP: %s, data port: 50009)\n",
                   WiFi.localIP().toString().c_str());