fw: robust HTTP body reads, CORS preflight, LED off at boot; update docs

- app_net.c: replace bare httpd_req_recv with recv_body_capped/alloc
  helpers (TCP-safe, full-body reads); add OPTIONS/* CORS preflight
  handler; bump WS broadcast buffer to 2048; add CORS Allow-Methods
- CMakeLists (net_service): add http_parser dep for HTTP_OPTIONS
- nfc_engine/pn532_core: add nfc_access_lock/unlock mutex, board-RGB
  quiet helper, UL type detection, general-status improvements
- pn532_transport: minor cleanup
- main.c: call board_rgb_led_quiet() at boot to kill onboard LED
- sdkconfig.defaults: add board RGB Kconfig defaults
- README, docs/LIMITATIONS, docs/PINOUT: expand and correct

Made-with: Cursor

firmware/components/pn532_host/pn532_transport.c

@@ -352,7 +352,7 @@ esp_err_t pn532_transport_exchange(const uint8_t *tx_body, size_t tx_body_len, u
 #if defined(CONFIG_PN532_TRANSPORT_SPI)
     ESP_RETURN_ON_ERROR(spi_write_frame(frame, pos), TAG, "spi wr");
 #elif defined(CONFIG_PN532_TRANSPORT_I2C)
-    i2c_wakeup();
+    ESP_RETURN_ON_ERROR(i2c_wakeup(), TAG, "i2c wake");
     ESP_RETURN_ON_ERROR(i2c_write_raw(frame, pos), TAG, "i2c wr");
 #elif defined(CONFIG_PN532_TRANSPORT_HSU)
     ESP_RETURN_ON_ERROR(hsu_write_raw(frame, pos), TAG, "hsu wr");