Clarify return value documentation in serial interface headers

- Updated return value descriptions in multiple serial interface header files to specify that negative error codes are derived from ::cpp_core::StatusCodes. This change enhances clarity and consistency in the documentation.

These updates improve the understanding of function outcomes across the serial API.

Author: Katze719

include/cpp_core/interface/serial_abort_read.h

@@ -16,7 +16,7 @@ extern "C"
      *
      * @param handle Port handle.
      * @param error_callback [optional] Callback to invoke on error. Defined in error_callback.h. Default is `nullptr`.
-     * @return 0 on success or a negative error code on failure.
+     * @return 0 on success or a negative error code from ::cpp_core::StatusCodes on error.
      */
     MODULE_API auto serialAbortRead(
         int64_t        handle,

include/cpp_core/interface/serial_abort_write.h

@@ -16,7 +16,7 @@ extern "C"
      *
      * @param handle Port handle.
      * @param error_callback [optional] Callback to invoke on error. Defined in error_callback.h. Default is `nullptr`.
-     * @return 0 on success or a negative error code on failure.
+     * @return 0 on success or a negative error code from ::cpp_core::StatusCodes on error.
      */
     MODULE_API auto serialAbortWrite(
         int64_t        handle,

include/cpp_core/interface/serial_clear_buffer_in.h

@@ -16,7 +16,7 @@ extern "C"
      *
      * @param handle Port handle.
      * @param error_callback [optional] Callback to invoke on error. Defined in error_callback.h. Default is `nullptr`.
-     * @return 0 on success or a negative error code on failure.
+     * @return 0 on success or a negative error code from ::cpp_core::StatusCodes on error.
      */
     MODULE_API auto serialClearBufferIn(
         int64_t        handle,

include/cpp_core/interface/serial_clear_buffer_out.h

@@ -16,7 +16,7 @@ extern "C"
      *
      * @param handle Port handle.
      * @param error_callback [optional] Callback to invoke on error. Defined in error_callback.h. Default is `nullptr`.
-     * @return 0 on success or a negative error code on failure.
+     * @return 0 on success or a negative error code from ::cpp_core::StatusCodes on error.
      */
     MODULE_API auto serialClearBufferOut(
         int64_t        handle,

include/cpp_core/interface/serial_close.h

@@ -16,7 +16,7 @@ extern "C"
      *
      * @param handle Handle obtained from serialOpen().
      * @param error_callback [optional] Callback to invoke on error. Defined in error_callback.h. Default is `nullptr`.
-     * @return 0 on success or a negative error code on failure.
+     * @return 0 on success or a negative error code from ::cpp_core::StatusCodes on error.
      */
     MODULE_API auto serialClose(
         int64_t        handle,

include/cpp_core/interface/serial_drain.h

@@ -29,7 +29,7 @@ extern "C"
      *
      * @param handle Port handle.
      * @param error_callback [optional] Callback to invoke on error. Defined in error_callback.h. Default is `nullptr`.
-     * @return 0 on success or a negative error code on failure.
+     * @return 0 on success or a negative error code from ::cpp_core::StatusCodes on error.
      */
     MODULE_API auto serialDrain(
         int64_t        handle,

include/cpp_core/interface/serial_get_ports_info.h

@@ -15,7 +15,7 @@ extern "C"
      *
      * @param callback_fn Callback receiving port information.
      * @param error_callback [optional] Callback to invoke on error. Defined in error_callback.h. Default is `nullptr`.
-     * @return Number of ports found or a negative error code.
+     * @return Number of ports found or a negative error code from ::cpp_core::StatusCodes on error.
      */
     MODULE_API auto serialGetPortsInfo(
         void (*callback_fn)(

include/cpp_core/interface/serial_in_bytes_total.h

@@ -13,7 +13,7 @@ extern "C"
      *
      * @param handle Port handle.
      * @param error_callback [optional] Callback to invoke on error. Defined in error_callback.h. Default is `nullptr`.
-     * @return Total number of bytes read or a negative error code.
+     * @return Total number of bytes read or a negative error code from ::cpp_core::StatusCodes on error.
      */
     MODULE_API auto serialInBytesTotal(
         int64_t        handle,

include/cpp_core/interface/serial_in_bytes_waiting.h

@@ -24,7 +24,7 @@ extern "C"
      *
      * @param handle Port handle.
      * @param error_callback [optional] Callback to invoke on error. Defined in error_callback.h. Default is `nullptr`.
-     * @return Bytes available for instant reading or a negative error code.
+     * @return Bytes available for instant reading or a negative error code from ::cpp_core::StatusCodes on error.
      */
     MODULE_API auto serialInBytesWaiting(
         int64_t        handle,

include/cpp_core/interface/serial_open.h

@@ -23,7 +23,7 @@ extern "C"
      * @param parity 0 = none, 1 = even, 2 = odd.
      * @param stop_bits 0 = 1 stop bit, 2 = 2 stop bits.
      * @param error_callback [optional] Callback to invoke on error. Defined in error_callback.h. Default is `nullptr`.
-     * @return A positive opaque handle on success or a negative value on failure.
+     * @return A positive opaque handle on success or a negative value from ::cpp_core::StatusCodes on failure.
      */
     MODULE_API auto serialOpen(
         void          *port,