Initial vx4b support

[uvvpavel]

No description provided.

[Copilot]

Pull request overview

Adds initial vx4b enablement across build, CI, and examples by updating dependencies and adjusting architecture-specific build/parallelization behavior.

Changes:

• Update build integration to use ai_tools (CMake subproject/target) and bump xmos-ai-tools / py_voice test dependencies.
• Add vx4b-specific handling in VNR model export (xcore-opt target arch + threshold) and AEC parallel compilation guards.
• Convert app_pipeline example from multi-tile to single-tile multi-thread (channel + PAR_JOBS) and adjust metadata layout.

Reviewed changes

Copilot reviewed 22 out of 23 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tests/stage_b/CMakeLists.txt	Add ai_tools and normalize sandbox dependency inclusion.
tests/requirements_test.txt	Bump Python test dependencies (xmos-ai-tools, py_voice).
tests/profile_memory/lib_voice_memory.json	Update recorded memory numbers.
tests/profile_memory/lib_voice_memory_table.rst	Update memory table value for VNR.
tests/lib_vnr/test_vnr_cffi/CMakeLists.txt	Add ai_tools to dependency subdirectories.
tests/lib_ic/py_c_frame_compare/CMakeLists.txt	Add ai_tools to dependency subdirectories.
tests/custom_cmake_build/CMakeLists.txt	Add ai_tools to dependency subdirectories.
requirements.txt	Bump xmos-ai-tools version.
lib_voice/vnr_model.cmake	Add vx4b arch handling for model export and set xcore-opt target arch.
lib_voice/src/vnr/vnr.c	Simplify init error handling (now assert-based).
lib_voice/src/aec/aec_process_frame.c	Enable parallel header/paths for __VX4B__.
lib_voice/lib_build_info.cmake	Update dependent modules, add arch-specific warning suppressions, adjust linking expectations.
lib_voice/CMakeLists.txt	Link VNR module against ai_tools instead of tflite_micro.
Jenkinsfile	Update shared library and add CI build path for vx4b tools/build.
examples/app_vnr/CMakeLists.txt	Allow external override of APP_HW_TARGET.
examples/app_pipeline/src/pipeline.c	Rename tile→thread APIs and adjust metadata usage.
examples/app_pipeline/src/pipeline_state.h	Change metadata type and rename state structs (tile→thread).
examples/app_pipeline/src/main.xc	Remove multi-tile XC main.
examples/app_pipeline/src/app.c	Add single-tile threaded main using channels + PAR_JOBS.
examples/app_pipeline/CMakeLists.txt	Allow external override of APP_HW_TARGET.
examples/app_aec/CMakeLists.txt	Allow external override of APP_HW_TARGET.
doc/rst/examples/index.rst	Update literalinclude snippet to match metadata API change.
CHANGELOG.rst	Add UNRELEASED entry for vx4b support + related changes.

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[xalbertoisorna]

looks good!

the assert point is out of scope but good to note somewhere.

[xalbertoisorna]

nice!