Drift follow-up: 5 deferred omega b5ab3fe94304 mirrors recorded as divergences in #203 #204

#203 (Refs #201) recorded these paths as divergences in tools/extract/drift-baseline.tsv instead of mirroring them from omega-mv b5ab3fe94304:

• src/omega_gpu_session.h (comment changes)
• tests/gpu_attention_test.c
• tests/gpu_pfgemm_test.c
• tests/gpu_prefill_attn_test.c
• tests/gpu_qgemm_test.c

Done when

Each path is either mirrored byte-identically from omega, with its baseline row removed and host tests still passing, or kept as a divergence with a reason that says why it can't be mirrored. Mirrors must be straight syncs under ADR 0043 with no rework of frozen code. Coverage is host-only, and anything chip-dependent stays NOT_RUN on GB10.

— Grokbot