[Refactor][CI] Unify skip-ci targeting and mirror_hardwares pipeline presets (#5254)

Signed-off-by: wangyu <410167048@qq.com>
Signed-off-by: wangyu <53896905+yenuo26@users.noreply.github.com>
Signed-off-by: [Your Name] [Your Email]
Co-authored-by: Weiming Liao <fayespica@outlook.com>

docs/contributing/README.md

@@ -71,7 +71,7 @@ For additional features and advanced configurations, refer to the:
 ### Testing
 
 vLLM-Omni uses `pytest` to test the codebase.
-Please refer to the [test instructions](./ci/test_guide.md) for detailed testing information.
+Please refer to the [test instructions](./ci/test_execution_guide.md) for detailed testing information.
 
 !!! warning
     Currently, not all unit tests pass when run on CPU platforms. If you don't have access to a GPU platform to run unit tests locally, rely on the continuous integration system to run the tests for now.
@@ -127,11 +127,11 @@ The skill offers two modes:
 The precheck covers five PR types: Bug Fix, Performance, New Model, Diffusion Model, and General. Each type has a tailored checklist that validates evidence quality (repro steps, A/B benchmarks, registry entries, etc.). See the [precheck-pr skill](https://github.com/vllm-project/vllm-omni/blob/main/.claude/skills/precheck-pr/SKILL.md) for the full checklist.
 
 ### Local Test
-Please run the L1 and L2 test cases locally first and attach the results before contacting us to add the "ready" label. Please refer to the [test instructions](./ci/test_guide.md) for running the test cases.
+Please run the L1 and L2 test cases locally first and attach the results before contacting us to add the "ready" label. Please refer to the [test instructions](./ci/test_execution_guide.md) for running the test cases.
 
 ### Automatic skip-ci (docs and pytest skip marks)
 
-On pull requests and `main` pushes, the bootstrap step in [`.buildkite/cuda/pipeline.yml`](https://github.com/vllm-project/vllm-omni/blob/main/.buildkite/cuda/pipeline.yml) runs [`.buildkite/cuda/scripts/upload_pipeline.py`](https://github.com/vllm-project/vllm-omni/blob/main/.buildkite/cuda/scripts/upload_pipeline.py) against the git diff. When every changed file qualifies, **L2 (`ready`) and L3 (`merge-test`) pipelines are not uploaded**, so the default GPU CI jobs are skipped.
+On pull requests and `main` pushes, the bootstrap step in [`.buildkite/cuda/pipeline.yml`](https://github.com/vllm-project/vllm-omni/blob/main/.buildkite/cuda/pipeline.yml) runs [`.buildkite/common/scripts/upload_pipeline.py`](https://github.com/vllm-project/vllm-omni/blob/main/.buildkite/common/scripts/upload_pipeline.py) against the git diff. When every changed file qualifies, **L2 (`ready`) and L3 (`merge-test`) pipelines are not uploaded**, so the default GPU CI jobs are skipped.
 
 | Change per file | Examples |
 | --- | --- |
@@ -148,7 +148,7 @@ These PR shapes all trigger skip-ci:
 Skip-ci does **not** apply when the diff also touches product code (for example `vllm_omni/`), or when test files change assertions, imports, fixtures, or other non-skip logic. If the diff cannot be resolved (non-PR branches outside `main`), CI runs as usual.
 
 !!! note
-    Skipping L2/L3 does **not** disable the Docker image build step. Nightly (L4) upload can still run when the PR has a `nightly-test` label or on scheduled `main` builds with `NIGHTLY=1`. See [CI levels](./ci/CI_5levels.md) for how bootstrap skip-ci relates to diff-gated E2E jobs.
+    Skipping L2/L3 does **not** disable the Docker image build step. Nightly (L4) upload can still run when the PR has a `nightly-test` label or on scheduled `main` builds with `NIGHTLY=1`. Bootstrap child steps live in `bootstrap-upload-steps.yml`; the hook entry step runs `upload_pipeline.py --upload <platform>/bootstrap-upload-steps.yml`, which injects `if` by step `key` from skip-ci before upload. See [CI Settings — Diff-aware CI](./ci/ci_settings.md#diff-aware-ci) and [Test System Overview](./ci/test_system_overview.md).
 
 ### Code Quality