* test: migrate legacy unit dirs and unrun folders into tests/unit, tests/integration and tests/e2e
* test: fix disk cache collection, ungate saturation check, drop RSS memory tests
* test: assert one delivered log per completion in Datadog and LangSmith checks
* test: drop SDK-direct e2e copies and align cost-map path filter cases
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Co-authored-by: yuneng <yuneng@berri.ai>
