feat(gateway): Update SDK configuration and add 485 control bridge

- Changed flash size configuration from 16MB to 4MB and updated partition table filename.
- Introduced two gateway channels with UART configurations for communication.
- Added support for gateway cache and startup services including BLE and Wi-Fi.
- Enabled SPI RAM and configured its parameters for better memory management.
- Enhanced the gateway bridge service to handle generated Modbus points more efficiently.
- Refactored the gateway Modbus component to improve point management and added new methods for point description and generation.
- Implemented a new Gateway485ControlBridge for handling 485 control communication with UART.
- Added necessary files for the 485 control bridge including configuration and implementation.

Signed-off-by: Tony <tonylu@tony-cloud.com>

components/gateway_485_control/include/gateway_485_control.hpp

@@ -0,0 +1,47 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <vector>
+
+#include "esp_err.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+
+namespace gateway {
+
+class GatewayController;
+
+struct Gateway485ControlBridgeConfig {
+  bool enabled{false};
+  int tx_pin{-1};
+  int rx_pin{-1};
+  uint32_t baudrate{9600};
+  size_t rx_buffer_size{256};
+  size_t tx_buffer_size{256};
+  uint32_t read_timeout_ms{20};
+  uint32_t write_timeout_ms{20};
+  uint32_t task_stack_size{4096};
+  UBaseType_t task_priority{4};
+};
+
+class Gateway485ControlBridge {
+ public:
+  Gateway485ControlBridge(GatewayController& controller,
+                            Gateway485ControlBridgeConfig config = {});
+
+  esp_err_t start();
+
+ private:
+  static void TaskEntry(void* arg);
+  void taskLoop();
+  void handleBytes(const uint8_t* data, size_t len);
+  void handleGatewayNotification(const std::vector<uint8_t>& frame);
+
+  GatewayController& controller_;
+  Gateway485ControlBridgeConfig config_;
+  TaskHandle_t task_handle_{nullptr};
+  bool started_{false};
+};
+
+}  // namespace gateway