Phase 3: Nostr identity derivation + wifistr service discovery

- Add identity.c/h: HMAC-SHA512 derivation from nsec → npub, STA/AP MAC, SSID, AP IP
- Add nostr_event.c/h: NIP-01 event serialization + Schnorr signing (BIP-340)
- Add geohash.c/h: lat/lon to geohash encoding
- Add wifistr.c/h: kind 38787 event builder + WebSocket publish to Nostr relays
- Update config.c/h: nsec-based identity, Nostr relay/geo config, remove static SSID/IP
- Replace custom mbedTLS wallet with nucula library (libsecp256k1)
- Remove wallet.c/h, wallet_persist.c/h (replaced by nucula_lib component)
- Verified on Board A: derived SSID, captive portal, payment, wallet, wifistr publish

1 files changed, 26 insertions, 5 deletions

diff --git a/main/tollgate_main.c b/main/tollgate_main.c
index d4b29bc..7fa1be1 100644
--- a/main/tollgate_main.c
+++ b/main/tollgate_main.c
@@ -11,12 +11,14 @@
 #include "lwip/dns.h"
 #include "dhcpserver/dhcpserver.h"
 #include "config.h"
+#include "identity.h"
 #include "dns_server.h"
 #include "captive_portal.h"
 #include "firewall.h"
 #include "session.h"
 #include "tollgate_api.h"
-#include "wallet.h"
+#include "nucula_wallet.h"
+#include "wifistr.h"
 
 #define MAX_STA_RETRY 5
 static const char *TAG = "tollgate_main";
@@ -92,8 +94,16 @@ static void ip_event_handler(void *arg, esp_event_base_t event_base,
 static void wallet_init_task(void *pvParameters)
 {
     const tollgate_config_t *cfg = tollgate_config_get();
-    wallet_init();
-    wallet_fetch_keysets(cfg->mint_url);
+    nucula_wallet_init(cfg->mint_url);
+    vTaskDelete(NULL);
+}
+
+static void publish_wifistr_task(void *pvParameters)
+{
+    vTaskDelay(pdMS_TO_TICKS(5000));
+    wifistr_publish();
+    const tollgate_config_t *cfg = tollgate_config_get();
+    wifistr_start_periodic(cfg->nostr_publish_interval_s);
     vTaskDelete(NULL);
 }
 
@@ -123,6 +133,8 @@ static void start_services(void)
     captive_portal_start(cfg->ap_ip_str);
     tollgate_api_start();
 
+    xTaskCreate(publish_wifistr_task, "wifistr_init", 16384, NULL, 3, NULL);
+
     s_services_running = true;
     if (s_services_mutex) xSemaphoreGive(s_services_mutex);
     ESP_LOGI(TAG, "=== TollGate services started ===");
@@ -214,7 +226,11 @@ void app_main(void)
     ESP_ERROR_CHECK(ret);
 
     ESP_ERROR_CHECK(tollgate_config_init());
+
+    ESP_ERROR_CHECK(identity_init(tollgate_config_get()->nsec));
+
     tollgate_config_derive_unique((tollgate_config_t *)tollgate_config_get());
+
     ESP_ERROR_CHECK(esp_netif_init());
     ESP_ERROR_CHECK(esp_event_loop_create_default());
 
@@ -227,6 +243,11 @@ void app_main(void)
     wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
     ESP_ERROR_CHECK(esp_wifi_init(&cfg));
 
+    const tollgate_config_t *tcfg = tollgate_config_get();
+    ESP_ERROR_CHECK(esp_wifi_set_mac(WIFI_IF_STA, tcfg->sta_mac));
+    ESP_ERROR_CHECK(esp_wifi_set_mac(WIFI_IF_AP, tcfg->ap_mac));
+    ESP_LOGI(TAG, "MACs set from identity");
+
     ESP_ERROR_CHECK(esp_event_handler_instance_register(WIFI_EVENT, ESP_EVENT_ANY_ID,
                                                          &wifi_event_handler, NULL, NULL));
     ESP_ERROR_CHECK(esp_event_handler_instance_register(IP_EVENT, IP_EVENT_STA_GOT_IP,
@@ -241,8 +262,8 @@ void app_main(void)
     wifi_config_t sta_config;
     if (tollgate_config_get_wifi(&sta_config) == ESP_OK) {
         ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_STA, &sta_config));
-        const tollgate_config_t *tcfg = tollgate_config_get();
-        ESP_LOGI(TAG, "STA configured for SSID: %s", tcfg->networks[tcfg->current_network].ssid);
+        const tollgate_config_t *tcfg2 = tollgate_config_get();
+        ESP_LOGI(TAG, "STA configured for SSID: %s", tcfg2->networks[tcfg2->current_network].ssid);
     }
 
     ESP_ERROR_CHECK(esp_wifi_start());