[BUG] `CUTE_DSL_KEEP=sass` is ignored in cutlass-dsl 4.6.0

### Which component has the problem? CuTe DSL ### Bug Report `nvidia-cutlass-dsl==4.6.0` documents `CUTE_DSL_KEEP=sass`, and the deprecated `CUTE_DSL_KEEP_SASS=1` warning recommends it, but the consolidated env var does not enable SASS dumping. Minimal repro: ```python from __future__ import annotations import os import subprocess import sys CHECK = r""" import importlib.metadata as metadata import os from cutlass.base_dsl.env_manager import EnvironmentVarManager, _parse_keep_tokens m = EnvironmentVarManager("CUTE_DSL") print("version:", metadata.version("nvidia-cutlass-dsl")) print("CUTE_DSL_KEEP:", os.getenv("CUTE_DSL_KEEP")) print("CUTE_DSL_KEEP_SASS:", os.getenv("CUTE_DSL_KEEP_SASS")) print("parse('sass'):", sorted(_parse_keep_tokens("sass", "CUTE_DSL"))) print("keep_tokens:", sorted(m.keep_tokens)) print("keep_sass:", m.keep_sass) """ def check(label: str, env_update: dict[str, str]) -> bool: env = os.environ.copy() for key in ("CUTE_DSL_KEEP", "CUTE_DSL_KEEP_SASS"): env.pop(key, None) env.update(env_update) env["PYTHONWARNINGS"] = "ignore::DeprecationWarning" print(f"\n== {label} ==") output = subprocess.check_output([sys.executable, "-c", CHECK], env=env, text=True) print(output, end="") return "keep_sass: True" in output documented_works = check("documented CUTE_DSL_KEEP=sass", {"CUTE_DSL_KEEP": "sass"}) deprecated_works = check("deprecated CUTE_DSL_KEEP_SASS=1", {"CUTE_DSL_KEEP_SASS": "1"}) if not documented_works and deprecated_works: print("\nBUG: CUTE_DSL_KEEP=sass is ignored, but CUTE_DSL_KEEP_SASS=1 works.") raise SystemExit(1) ``` Observed: ```text == documented CUTE_DSL_KEEP=sass == version: 4.6.0 CUTE_DSL_KEEP: sass CUTE_DSL_KEEP_SASS: None parse('sass'): [] keep_tokens: [] keep_sass: False == deprecated CUTE_DSL_KEEP_SASS=1 == version: 4.6.0 CUTE_DSL_KEEP: None CUTE_DSL_KEEP_SASS: 1 parse('sass'): [] keep_tokens: ['sass'] keep_sass: True ``` Expected: `CUTE_DSL_KEEP=sass` should set `keep_tokens == ["sass"]` and `keep_sass == True`. Likely fix: add `"sass"` to the accepted `CUTE_DSL_KEEP` token set used by `_parse_keep_tokens`.