docs(esp_trace): restructure tracing docs with esp_trace as master

Reorganize the tracing documentation so esp_trace is the master
component, with app_trace, SystemView, and Gcov referenced from it.

(cherry picked from commit 6c6490d54c)

docs/zh_CN/api-reference/system/esp_trace.rst

@@ -0,0 +1,70 @@
+ESP Trace
+=========
+
+:link_to_translation:`en:[English]`
+
+概述
+----
+
+``esp_trace`` 组件是 ESP-IDF 跟踪的入口。它提供公共跟踪 API，管理活动跟踪会话，并将所选编码器（如 SEGGER SystemView）与所选传输（如 apptrace）连接起来。
+
+有关概念概览、架构和使用指南，请参阅 :doc:`/api-guides/tracing/index`。
+
+应用示例
+--------
+
+- :example:`system/esp_trace_custom_library` 演示如何将外部跟踪库（编码器）与 ``esp_trace`` 核心集成。
+
+API 参考
+--------
+
+类型
+^^^^
+
+.. doxygentypedef:: esp_trace_handle_t
+
+.. doxygenstruct:: esp_trace_open_params_t
+    :members:
+
+.. doxygenstruct:: esp_trace_config
+    :members:
+
+.. doxygenenum:: esp_trace_link_types_t
+
+适配器类型
+^^^^^^^^^^
+
+.. doxygenstruct:: esp_trace_encoder_vtable_t
+    :members:
+
+.. doxygenstruct:: esp_trace_encoder
+    :members:
+
+.. doxygenenum:: esp_trace_transport_cfg_key_t
+
+.. doxygenstruct:: esp_trace_transport_vtable_t
+    :members:
+
+.. doxygenstruct:: esp_trace_transport
+    :members:
+
+函数
+^^^^
+
+.. doxygenfunction:: esp_trace_get_user_params
+
+.. doxygenfunction:: esp_trace_get_active_handle
+
+.. doxygenfunction:: esp_trace_write
+
+.. doxygenfunction:: esp_trace_start
+
+.. doxygenfunction:: esp_trace_stop
+
+.. doxygenfunction:: esp_trace_flush
+
+.. doxygenfunction:: esp_trace_is_host_connected
+
+.. doxygenfunction:: esp_trace_get_link_type
+
+.. doxygenfunction:: esp_trace_panic_handler

docs/zh_CN/api-reference/system/index.rst

@@ -9,6 +9,7 @@
     app_image_format
     bootloader_image_format
     app_trace
+    esp_trace
     esp_function_with_shared_stack
     chip_revision
     console