feat: add feishu bot header api

Signed-off-by: Asklv <boironic@gmail.com>

main/channels/feishu/feishu_bot.h

@@ -0,0 +1,36 @@
+#pragma once
+
+#include "esp_err.h"
+
+/**
+ * Initialize the Feishu bot (load credentials from NVS / build-time).
+ */
+esp_err_t feishu_bot_init(void);
+
+/**
+ * Start the Feishu webhook HTTP server for receiving events.
+ * Listens on MIMI_FEISHU_WEBHOOK_PORT.
+ */
+esp_err_t feishu_bot_start(void);
+
+/**
+ * Send a text message to a Feishu chat.
+ * Automatically splits messages longer than MIMI_FEISHU_MAX_MSG_LEN chars.
+ * @param chat_id  Feishu chat ID (open_id or chat_id)
+ * @param text     Message text
+ */
+esp_err_t feishu_send_message(const char *chat_id, const char *text);
+
+/**
+ * Reply to a specific message in a Feishu chat.
+ * @param message_id  The message_id to reply to
+ * @param text        Reply text
+ */
+esp_err_t feishu_reply_message(const char *message_id, const char *text);
+
+/**
+ * Save Feishu app credentials to NVS.
+ * @param app_id     Feishu App ID
+ * @param app_secret Feishu App Secret
+ */
+esp_err_t feishu_set_credentials(const char *app_id, const char *app_secret);