feat: WiFi country code DE + retry delay + updated docs

- Add esp_wifi_set_country_code('DE') before WiFi start for EU regulatory compliance
- Add 2s delay between WiFi auth retries to avoid AP rate limiting
- Update AGENTS.md with CVM modules, board C, per-board locks, WiFi notes
- Update CHECKLIST.md with Phase 7b completion, 7c integration progress
- Update PLAN.md with test cases 53-73, WiFi country code findings
- Update Makefile port defaults (A=ACM0, B=ACM1)
- Board B connects to WiFi successfully with these fixes
- Board A has hardware WiFi issue (auth fails on all APs)

1 files changed, 4 insertions, 0 deletions

diff --git a/main/tollgate_main.c b/main/tollgate_main.c
index c0ff65f..ad5211a 100644
--- a/main/tollgate_main.c
+++ b/main/tollgate_main.c
@@ -56,6 +56,7 @@ static void wifi_event_handler(void *arg, esp_event_base_t event_base,
         tollgate_client_on_sta_disconnected();
         if (s_services_running) stop_services();
         if (s_retry_count < MAX_STA_RETRY) {
+            vTaskDelay(pdMS_TO_TICKS(2000));
             esp_wifi_connect();
         } else {
             wifi_config_t wifi_cfg;
@@ -305,6 +306,9 @@ void app_main(void)
         ESP_LOGI(TAG, "STA configured for SSID: %s", tcfg2->networks[tcfg2->current_network].ssid);
     }
 
+    ESP_ERROR_CHECK(esp_wifi_set_country_code("DE", false));
+    ESP_LOGI(TAG, "WiFi country code set to DE (EU regulatory domain)");
+
     ESP_ERROR_CHECK(esp_wifi_start());
 
     ESP_LOGI(TAG, "WiFi AP+STA started, waiting for connection...");