[recipe] fix: Resync Kimi K2.5-VL pipeline layout

[yaoyu-33]

Problem

The Kimi K2.5-VL H100 recipe materializes a static PP=16, VP=1 pipeline layout but does not register its existing layout builder. A supported public runner override such as --recipe kimi_k25_vl_sft_config -pp 4 -vp 1 therefore leaves the 16-stage layout unchanged. Megatron-Core derives VP=4 from that stale layout and rejects the explicit VP=1 setting; with only -pp 4, it can silently use VP=4 instead of the recipe's declared PP=4, VP=1 topology.

The path is run_recipe override application -> sync_model_pipeline_layout -> Kimi K2.5-VL recipe model config -> Megatron-Core pipeline-layout validation.

Fix

Register the recipe's existing _get_kimi_k25_vl_pipeline_layout function as _pipeline_model_parallel_layout_builder. The shared runner then rebuilds recipe-owned layouts after supported PP/VP overrides while preserving explicit user-provided layouts.

This is the same ownership pattern already used by the Kimi K2 recipe. No public API, dependency, CI, or Megatron-Core changes are included.

Validation

Regression test on the unmodified base revision:

uv run python -m pytest --confcutdir=tests/unit_tests/recipes/kimi_vl tests/unit_tests/recipes/kimi_vl/test_kimi_k25_vl.py -k pipeline_layout_tracks_supported_runner_override -q
1 failed, 31 deselected

The failure was the stale 16-entry layout instead of the expected four-entry PP=4, VP=1 layout.

The unchanged test after the fix:

uv run python -m pytest --confcutdir=tests/unit_tests/recipes/kimi_vl tests/unit_tests/recipes/kimi_vl/test_kimi_k25_vl.py -k pipeline_layout_tracks_supported_runner_override -q
1 passed, 31 deselected

Adjacent recipe tests:

uv run python -m pytest --confcutdir=tests/unit_tests/recipes tests/unit_tests/recipes/kimi/test_kimi_k2.py tests/unit_tests/recipes/kimi_vl/test_kimi_k25_vl.py -q
54 passed

uv run python -m pytest --confcutdir=tests/unit_tests/scripts/training tests/unit_tests/scripts/training/test_recipe_runner.py tests/unit_tests/scripts/training/test_run_recipe.py -k 'pipeline_layout or kimi_supported_pp_vp_override' -q
6 passed, 163 deselected

git diff --check and uv run pre-commit run --all-files also passed.

Scope

This change only resynchronizes the Kimi K2.5-VL recipe-owned layout for the topologies already declared by its helper. It does not add new parallel configurations or claim GPU, convergence, performance, or full-suite validation.

Related prior Kimi K2 fix: #5008.

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[yaoyu-33]

/ok to test d132e40

[claude]

LGTM - light review complete.

The fix registers _get_kimi_k25_vl_pipeline_layout as _pipeline_model_parallel_layout_builder, mirroring the established ownership pattern in kimi/h100/kimi_k2.py:124, deepseek/h100/deepseek_v3.py:154, and exaone/h100/exaone_moe.py:134. sync_model_pipeline_layout (scripts/training/recipe_runner.py:390) reads that attribute to rebuild recipe-owned layouts after supported -pp/-vp overrides while preserving an explicit user-provided pipeline_model_parallel_layout. Without it, a -pp 4 -vp 1 override left the stale 16-stage layout in place - the exact bug the PR describes.

Verified:

• The builder supports (4, 1) in map_pp_vp_to_layout, so the new test assertion resolves to a real layout, not the ValueError path.
• The test import (_load_recipe_runner_module) and the compatibility alias kimi_k25_vl_sft_config both resolve.
• No bugs, typos, or doc drift. Coverage for the changed contract is adequate.

No 3rdparty/Megatron-LM boundary touched; no public API or dependency change.

Suggested test cases:

• tests/unit_tests/recipes/kimi_vl/test_kimi_k25_vl.py::test_sft_config_pipeline_layout_tracks_supported_runner_override
• tests/unit_tests/recipes/kimi_vl/test_kimi_k25_vl.py::test_sft_config_pipeline_layout_matches_helper
• No perf tests impacted.

[yaoyu-33]

/ok to test d132e40

[yaoyu-33]

/ok to test cc3dbde