Move 7 trace-related examples (app_trace_basic, app_trace_to_plot,
esp_trace_custom_library, function_tracing, gcov, sysview_tracing,
sysview_tracing_heap_log) from examples/system/ into a dedicated
examples/system/tracing/ subdirectory for better organization.
Update all path references across documentation (en + zh_CN),
build-test-rules, CI configs, Kconfig, and component READMEs.
The hw-reference/modules-and-boards page was removed from esp-idf docs
and moved to esp-dev-kits. The ESP32-S2-Saola-1 user guide similarly
moved. The configure-builtin-jtag link used the now-obsolete chip-less
stable URL format.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
