s1122 — χ menu on the non-blind chains
  menu: 16 members in [0.0213, 0.6180] T₃ · log-coverage at ±5% ≤ 47% (declared) · c1107 fitted χ = 0.05588 T₃ (Ca chain, NOT blind)
  χ/T₃           N=28 i   N=50 i   N=82 i   Ca(cons)  Sn(cons)
  φ⁻8              0.26     0.26     0.34       0.39      0.43
  φ⁻7              0.32     0.33     0.44       0.61      0.69
  φ⁻6              0.42     0.44     0.59       0.96      1.09
  R₃               0.43     0.46     0.61       1.01      1.15
  φ⁻5              0.57     0.62     0.84       1.53      1.75   ← passes all three isotone bars
  1/7 (DET-7)      0.81     0.89     1.21       2.41      2.76   ← passes all three isotone bars
  φ⁻4              0.83     0.90     1.24       2.46      2.81   ← passes all three isotone bars
  R₂               0.94     1.03     1.41       2.87      3.29   ← passes all three isotone bars
  ½φ⁻²             1.03     1.14     1.56       3.21      3.67   ← passes all three isotone bars
  φ⁻3              1.24     1.37     1.88       3.95      4.53   ← passes all three isotone bars
  ½φ⁻¹             1.57     1.74     2.40       5.16      5.93
  φ⁻2              1.91     2.12     2.93       6.38      7.32
  3/7              2.12     2.36     3.26       7.15      8.21
  7/16             2.16     2.40     3.32       7.30      8.38
  ½ (Peirce)       2.45     2.72     3.77       8.33      9.57
  φ⁻1              2.99     3.33     4.62      10.29     11.83
  members passing all three isotone bars: ['φ⁻5', '1/7 (DET-7)', 'φ⁻4', 'R₂', '½φ⁻²', 'φ⁻3']
  [PASS] at least one member passes (else the Casimir form itself is wrong for isotones)
  [FAIL] the passing set is NOT dense (≤ 3 of the menu) — otherwise the bar cannot select
  FIXED-Z DISCRIMINATOR (the isospin-dominated chains, Casimir form): members within 15% of BOTH Ca and Sn: ['φ⁻6']
  [PASS] exactly one member closes both fixed-Z chains within 15% — the Casimir coefficient is SELECTED by the isospin chains, not by the isotones
  caveat: Ca was c1107's FIT target (φ⁻⁶ is −0.27% from that fit, so Ca 0.96 is not independent); Sn was SPENT as a Coulomb target
  (A1545) but never used for χ — its 1.09 is the one independent consistency hit. The isotone chains (all at MAGIC N = 28/50/82)
  remain 2× short even with χ: a shell-stiffening term at closed shells — P3's object (A1545), not isospin's.
  nearest member to c1107's fitted χ: φ⁻6 = 0.05573 (-0.27%) — fodder until a derivation names the power

VERDICT (bars above): which registered weights make the isotone curvature close on top of count×½ Coulomb, with the Ca and
  Sn chains shown as consistency only. A single passer is a CANDIDATE χ for the blind lines (s1123 pre-commit); several = a
  dense menu and the blind lines decide; none = the Casimir form is not the isospin sector's shape. Nothing prints.

s1122: A CHECK FAILED
