v1.23.0 — the feature we tested and did not ship

A feature we promised, tested, and did not ship - plus the finding that replaced it.

We told an external reporter (E-08, RTX 5070) that this release would turn the all-in-VRAM
FLOOR into a point estimate, using the 61 public benchmarks we had collected. Pre-registration
#72 staked that with their measurement as the holdout. It failed its own gate and does not
ship. On one basis (efficiency = tok/s x file bytes / spec bandwidth) the public corpus spans
0.512-0.812 across 8 GPU architectures - and our 2016 Pascal card measures 0.509-0.577, INSIDE
that range. Their box sits at 0.810: the population maximum. Fitting a constant until their
number landed in band would have been the exact failure C-02 taught us to refuse.

• L-18 (new law): the all-in-VRAM spread is a property of the POPULATION, not of our old
  GPU and not of any architecture. 1.6x wide, irreducible from public data, collapsed only by
  measuring the specific machine. The floor advice now cites those 61 benchmarks as evidence
  and points at calibrate as the concrete fix instead of apologising.
• U-23 (shipped, with its limit stated): --no-mmap is no longer unconditional on expert
  splits. Above 75% of the usable RAM pool the emit keeps mmap so pages stay evictable, and
  says why - naming the +13.7% decode it is giving up. Honest limit, in the register: the gate
  reasons about model share, so it does NOT catch the reporter's own case (their 330 MiB free
  came from other processes and the mapped file). Reading actual available memory is U-24.
• The mark: quantprobe has an icon - old-style pixel art, one 12x12 bitmap that generates
  both the SVG and the terminal banner. Bare quantprobe now prints it (with plain-text
  fallbacks for pipes, NO_COLOR, and legacy Windows consoles).
• Register at 92 entries: E-08 (the first out-of-sample validation on hardware we do not own -
  58.1 predicted vs 54-57 measured), E-09 (rabbit: disk-tier bandwidth-indifference), L-18,
  U-23 closed, U-24 opened.