First-Principles Two-Field Bounce in the SFV/dSB Model

We present a detailed, reproducible computation of an O(4)-symmetric two-field Coleman bounce in the SFV/dSB framework. In this work, we address the numerical challenges of multi-field vacuum decay by employing a collocation method with an analytic Jacobian and adaptive continuation in the portal coupling, g. Building on our original report S_E ~= 1424 at v=9x10^-5, lambda,lambda_Phi=(1.3x10^-4,0.1), g=2.0, negative-branch, we expand derivations, specify the dimensionless Boundary Value Problem (BVP), and document our numerical protocol. The primary contribution is a complete, verifiable framework for studying the SFV/dSB model, supported by extensive convergence and robustness checks. We quantify a ``solvability corridor'' in the ratio of symmetry-breaking scales, rho ~ |v_Phi|v, making the ``Hierarchy of Origins'' a testable hypothesis. All artifacts, including configuration files, scripts, and output data, are provided to ensure full reproducibility. Curvature effects are confirmed to be negligible at the benchmark.