feat(M11.1): add exact pointwise CAT/EPT soliton carrier

[jagg-ix]

M11.1

Introduces a new M11 model lineage rather than extending M10.

The reference carrier is an exactly normalized cubic-NLS bright soliton on an odd pointwise grid. The finite-domain amplitude determines the cubic coupling, so the analytic second derivative closes

-D psi_xx - g psi^3 = mu psi

at machine precision. The standing-wave lift verifies the pointwise time equation and stationary density. A sinh-Gordon BPS algebra control checks both phi'' = sinh(phi) and the E=-1 first integral.

Formal authority

Pins entropic-physlib-linear-full@8bafa9ab and the exact source blobs for:

• SinhGordonSoliton.bps_implies_sinhGordon;
• SelfBoundSchrodingerNewtonPDE.standingWave_solves_full_schrodingerNewton;
• CubicQuinticOrbitalStability.cubicQuinticDensity_coercive.

Validation

Adds a dedicated M11 workflow that compiles the package, validates every M11 formal JSON ledger and runs tests/test_m11_*.py.

[jagg-ix]

Validation complete on 88d9fe6668b2b7a2b5a86601f93cb4f94502a458: M11 modules compiled, all formal ledgers validated, and all available test_m11_*.py tests passed in workflow run 30516055141. This is PR 1 of 5. Merge order: #151 -> #152 -> #153 -> #154 -> #155. Use Create a merge commit for the stacked series; squash-merging removes the parent commit used by the next PR.