Fix web OTA upload and isolate OTA sessions across firmware and goTool.

Split ESP-NOW into core/master/slave modules, block non-OTA UART traffic during updates, and hold the host serial port exclusively so dashboard polling cannot interleave with firmware uploads.

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

main/cmd/cmd_handler.c

@@ -1,4 +1,5 @@
 #include "cmd_handler.h"
+#include "ota_session.h"
 #include "esp_err.h"
 #include "esp_log.h"
 #include "freertos/FreeRTOS.h"
@@ -88,33 +89,19 @@ esp_err_t msg_register_handler(uint16_t id, msg_callback_t cb) {
   return ESP_OK;
 }
 
-esp_err_t msg_post(uint16_t id, const uint8_t *data, size_t len) {
-  if (cmd_queue == NULL) {
-    return ESP_ERR_INVALID_STATE;
-  }
-
-  generic_msg_t msg = {.msg_id = id, .len = len, .payload = NULL};
-  if (len > 0) {
-    msg.payload = malloc(len);
-    if (msg.payload == NULL) {
-      return ESP_ERR_NO_MEM;
-    }
-    memcpy(msg.payload, data, len);
-  }
-
-  if (xQueueSend(cmd_queue, &msg, pdMS_TO_TICKS(100)) != pdPASS) {
-    free(msg.payload);
-    return ESP_ERR_TIMEOUT;
-  }
-  return ESP_OK;
-}
-
 void vCmdDispatcherTask(void *param) {
   (void)param;
   generic_msg_t msg;
 
   while (1) {
     if (xQueueReceive(cmd_queue, &msg, portMAX_DELAY) == pdPASS) {
+      if (!ota_session_uart_cmd_allowed(msg.msg_id)) {
+        ESP_LOGW(TAG, "reject %s (0x%02x) during OTA session",
+                 message_type_name(msg.msg_id), (unsigned)msg.msg_id);
+        free(msg.payload);
+        continue;
+      }
+
       bool handled = false;
       for (int i = 0; i < handler_count; i++) {
         if (handlers[i].msg_id == msg.msg_id) {