DuckDB 영감. fd+offset+Buffer view 로 mmap 의미론 흉내. zero-dep.\\n\\nRepo: gogs.dclub.kr/kim/freelang-vcol (S0 4548994)\\nSPEC.airc 표준, 3 axis independence (effect/storage/build) lock.\\n\\nS1 layout + S2 access + S3 write 최소 스펙. S4 metric-store hybrid 는 후속 cycle.