============================================================================
OWNERSHIP PLATEAU (Paper 8: psi* ~ 0.10, leaving ~88-90% in active float)
============================================================================
Verified flow c = 0.39%/yr of market cap (Mode B). Test: does it plateau, where?

Central (c=0.39%, dur=40y, g=2%):
  share by year: Y20=6.8%  Y40=10.9%  Y80=10.9%  Y150=10.9%  Y240=10.9%
  PLATEAU (last 30y mean): 10.9%
  rising after plateau? last-50y slope: +0.0000%/yr (≈0 confirms plateau)

Sweep: plateau share vs holding duration and flow rate
   dur (y) c=0.30%  c=0.39%  c=0.50%  c=0.65%
        25   6.0%    7.8%   10.0%   12.9%
        30   6.9%    8.9%   11.4%   14.8%
        40   8.4%   10.9%   14.0%   18.1%
        50   9.6%   12.5%   16.0%   20.8%

READING: ownership plateaus in every case (no run to 1) -- the decumulation
bound holds structurally. The plateau LEVEL ranges ~7% to ~22% depending on
holding duration and flow; the paper's ~10% sits in the low-middle, at the
verified 0.39% flow and a moderate ~30-40y duration. The honest point: the
PLATEAU is robust (Proposition 4 holds); its LEVEL is duration-sensitive, and
at long durations / high floor-weighting it could reach ~20%, still leaving a
clear majority float but above the headline 10%.
