feat(mdns): restore mDNS + hostname kidsOS-XXXX

- Add espressif/mdns 1.3.2 to idf_component.yml + CMake
- STA path (esp32_wifi.cpp): set DHCP hostname kidsOS-XXXY from MAC,
  mdns_init, hostname, instance, _http:80 + _tactility:6666 services
- AP path (WebServerService.cpp): same hostname + mDNS for AP mode
- Log: mDNS AP/STA initialized hostname 'kidsOS-91ED.local'
- Previous implementation from 300ddb3a lost in driver arch migration
  f9453d89 (#562 #574)

Tested: RLCD 0x2d5470 FLASH_EXIT:0, log shows
  'mDNS AP initialized, hostname kidsOS-91ED.local'

Firmware/idf_component.yml

@@ -84,5 +84,6 @@ dependencies:
     version: "1.1.4"
     rules:
       - if: "target in [esp32s3, esp32p4]"
+  espressif/mdns: "1.3.2"
   idf: '5.5.2'
 

Platforms/platform-esp32/CMakeLists.txt

@@ -6,7 +6,7 @@ idf_component_register(
     SRCS ${SOURCES}
     INCLUDE_DIRS "include/"
     PRIV_INCLUDE_DIRS "private/"
-    REQUIRES TactilityKernel driver esp_adc esp_driver_i2c esp_lcd vfs fatfs esp_wifi esp_netif esp_event
+    REQUIRES TactilityKernel driver esp_adc esp_driver_i2c esp_lcd vfs fatfs esp_wifi esp_netif esp_event mdns
 )
 
 if (DEFINED ENV{ESP_IDF_VERSION})

Platforms/platform-esp32/source/drivers/esp32_wifi.cpp

@@ -5,9 +5,11 @@
 #if defined(CONFIG_SOC_WIFI_SUPPORTED) || defined(CONFIG_SLAVE_SOC_WIFI_SUPPORTED)
 
 #include <esp_event.h>
+#include <esp_mac.h>
 #include <esp_netif.h>
 #include <esp_wifi.h>
 #include <esp_wifi_default.h>
+#include <mdns.h>
 
 #include <tactility/concurrent/mutex.h>
 #include <tactility/device.h>
@@ -151,6 +153,31 @@ error_t bring_up_wifi(Esp32WifiCtx* ctx) {
         return ERROR_RESOURCE;
     }
 
+    // mDNS + hostname: kidsOS-XXXX from MAC, for Bonjour discovery
+    {
+        uint8_t mac[6];
+        char hostname[32];
+        if (esp_wifi_get_mac(WIFI_IF_STA, mac) == ESP_OK) {
+            snprintf(hostname, sizeof(hostname), "kidsOS-%02X%02X", mac[4], mac[5]);
+        } else {
+            strncpy(hostname, "kidsOS", sizeof(hostname));
+        }
+        LOG_I(TAG, "Setting DHCP hostname to '%s'", hostname);
+        esp_netif_set_hostname(ctx->netif, hostname);
+
+        esp_err_t mdns_err = mdns_init();
+        if (mdns_err == ESP_OK) {
+            LOG_I(TAG, "mDNS initialized, hostname '%s.local'", hostname);
+            mdns_hostname_set(hostname);
+            mdns_instance_name_set("kidsOS Tactility Device");
+            mdns_service_add(NULL, "_http", "_tcp", 80, NULL, 0);
+            mdns_service_add(NULL, "_tactility", "_tcp", 6666, NULL, 0);
+        } else {
+            LOG_W(TAG, "mDNS init failed: %s", esp_err_to_name(mdns_err));
+        }
+    }
+
+
     // Warning: this is the memory-intensive operation. It uses over 100kB of
     // RAM with default settings.
     wifi_init_config_t init_config = WIFI_INIT_CONFIG_DEFAULT();

Tactility/CMakeLists.txt

@@ -32,6 +32,7 @@ if (DEFINED ENV{ESP_IDF_VERSION})
         vfs
         fatfs
         lwip
+        mdns
         spi_flash
     )
 

Tactility/Source/service/webserver/WebServerService.cpp

@@ -46,6 +46,8 @@
 #include <esp_system.h>
 #include <esp_vfs_fat.h>
 #include <esp_wifi.h>
+#include <mdns.h>
+#include <esp_mac.h>
 #include <freertos/FreeRTOS.h>
 #include <freertos/task.h>
 #include <iomanip>
@@ -392,6 +394,27 @@ bool WebServerService::startApMode() {
     }
 
     LOG_I(TAG, "WiFi AP started - SSID: '%s', Channel: %u, IP: 192.168.4.1", settings.apSsid.c_str(), (unsigned)settings.apChannel);
+
+    // mDNS for AP mode too - kidsOS-XXXX.local
+    {
+        uint8_t mac[6];
+        char hostname[32];
+        if (esp_wifi_get_mac(WIFI_IF_AP, mac) == ESP_OK) {
+            snprintf(hostname, sizeof(hostname), "kidsOS-%02X%02X", mac[4], mac[5]);
+        } else {
+            strncpy(hostname, "kidsOS", sizeof(hostname));
+        }
+        esp_netif_set_hostname(apNetif, hostname);
+        esp_err_t mdns_err = mdns_init();
+        if (mdns_err == ESP_OK) {
+            LOG_I(TAG, "mDNS AP initialized, hostname '%s.local'", hostname);
+            mdns_hostname_set(hostname);
+            mdns_instance_name_set("kidsOS Tactility Device");
+            mdns_service_add(NULL, "_http", "_tcp", 80, NULL, 0);
+            mdns_service_add(NULL, "_tactility", "_tcp", 6666, NULL, 0);
+        }
+    }
+
     return true;
 }