[emulator] Fix docs stdout example and Python-bindings cmake fallback path

- docs/guide/emulator.md: the stdout callback example used sys.stdout without
  importing sys; use print(..., end='') so the snippet runs as shown.
- api/python/CMakeLists.txt: the non-BN_API_PATH include fell back to
  ${CMAKE_SOURCE_DIR}/api/cmake/..., which does not exist for an out-of-tree
  build; point it at the api root via a correct relative path (matching warp).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: xusheng6

docs/guide/emulator.md

@@ -242,7 +242,7 @@ emu.set_pre_instruction_hook(lambda emu, index: True)
 emu.set_intrinsic_hook(lambda emu, intrinsic, params: None)
 
 # stdout from emulated printf/puts/putchar; data is bytes.
-emu.set_stdout_callback(lambda emu, data: sys.stdout.write(data.decode('latin1')))
+emu.set_stdout_callback(lambda emu, data: print(data.decode('latin1'), end=''))
 
 # stdin for emulated getchar/fgets/fread; return up to max_len bytes, b'' for EOF.
 emu.set_stdin_callback(lambda emu, max_len: b'')

plugins/emulator/api/python/CMakeLists.txt

@@ -5,7 +5,8 @@ project(emulator-python-api)
 if(BN_API_PATH)
 	include(${BN_API_PATH}/cmake/PythonBindings.cmake)
 else()
-	include(${CMAKE_SOURCE_DIR}/api/cmake/PythonBindings.cmake)
+	# api/plugins/emulator/api/python -> api root is four levels up
+	include(${PROJECT_SOURCE_DIR}/../../../../cmake/PythonBindings.cmake)
 endif()
 
 file(GLOB PYTHON_SOURCES CONFIGURE_DEPENDS ${PROJECT_SOURCE_DIR}/*.py)