Constant VRAM_WARN_THRESHOLD_BYTES 

const VRAM_WARN_THRESHOLD_BYTES: usize = _; // 137_438_953_472usize

Advisory upper-bound for VRAM byte values (128 GiB).

Current max GPU VRAM is ~96 GiB (H100 SXM). Values above this threshold almost certainly indicate a unit error (e.g. GiB instead of bytes). We warn but do not clamp, so intentional overrides still work.