The M2 Soliton Function, Second Layer Closed: Flavor-Barrier Bags and the Spectral Fingerprint (v0.5)

We close the second layer (quark bag) of the M2 soliton-function program at criterion level. In BVP units (eta = sigma = 1) we deliver the complete six-flavor family of flavor-barrier bags: the cloud equation upgraded with a flavor barrier shell n_f * epsilon_0 on [rho_c, d*] and a flavor source Y_f = 2k+1 (the W-ladder, adopted as the Delta-S operationalization by arbitration), at working point (g, y) = (1, 1) with the canonical contact shell d* = 0.7999. The re-anchored family pp(k), the bag masses E_mass(k) under the dictionary-density definition, and the cloud excitation spectral fingerprint are certified into the anchor table with a C-line co-signed error budget (pp ±1.7e-6; E_mass below 0.001%; spectral ladder ±(1–3)e-4). Structural findings: the cloud spectrum is a barrier probe, not a Yukawa probe (the source term drops out of the fluctuation operator); the fingerprint reads +31.5% saturation of the ground vibrational mode with a flavor-blind rotational ladder; the d* scan resolves two regimes with a bag-breaking zone at d* > 1.5. Eight departures from standard-physics expectations are reported in full, and the E/W mass-law dip at charm is declared as an open item rather than fitted. All conclusions carry anchor labels and pre-registered falsification triggers.Keywordssoliton function; flavor barrier; spectral fingerprint; coarse-grained emergence; confined magnetic texture; anchor-label system; pre-registered falsification