v2.0.0-beta.18

Snapshots carry fewer zero pages, and restores copy fewer.

• TensorRails DMTCP v5.0.0-warmctl.2: a checkpoint leaves out resident
  memory that holds only zeros, and restart readers share the large runs
  between them. Baked with warmctl and restored on one RTX 3090, Qwen3-0.6B's
  process images fell from 8,582 to 6,065 MiB and time to /health from
  4.6–5.1 s to 4.0–4.4 s, with the same answers. Pinned CUDA host memory
  already left its zeros out, so Qwen3.8-Flash-Next's CPU-side embedding
  table is unchanged. Bake new snapshots with this release; images restart
  under either DMTCP version.
• up's stage copy (a snapshot on FUSE or stored with --compress) skips
  all-zero pages: the staged files keep holes there. More than half of a
  process image is zero pages (57% of GLM-5.3-Flash's CRIU images), and
  writing them took half of the stage. Staging those images into memory
  went from 3.96 to 7.23 GB/s from a compressed snapshot and to 8.48 GB/s
  from a raw one; weights, which have no zero pages, stage as before.