Fixed-endpoint integrability for production R-322 collapses #
This file closes the raw Bochner-integrability field in the production primitive certificate. The proof is pointwise at every nonzero external endpoint; it does not promote the almost-everywhere section supplied by Fubini.
A fixed nonzero endpoint makes the raw proper-block collapse absolutely integrable as soon as its predecessor and middle kernels have the paper's inverse-square bounds. This is a pointwise statement, not an a.e.-section consequence of joint Fubini.
At a fixed positive mollification scale, the Proposition 4.1 majorant
is bounded by one nonnegative constant times invSqKer + 1. The constant
may depend on the scale; only raw integrability is asserted here.
Reachability, the current edge certificate, and the Proposition 4.1 primitive bound prove raw collapse integrability at every nonzero endpoint. No a.e.-section theorem is used.
Production constructor for the actual primitive certificate, with its raw integrability field discharged from reachability and Proposition 4.1.