Structural reduction of the twin prime conjecture to a factorized Maynard-normalized form

This preprint presents a conditional structural reduction of the twin prime conjecture to a factorized Maynard-normalized bilinear estimate. The external input is Maynard's Lemma 6.11 from Primes in arithmetic progressions to large moduli III: uniform residue classes, used only in its factorized form over moduli q=q1 q2 q3. The internal contribution fixes the terminal residue class a=2, proves stability of the combined coefficients, classifies terminal and non-terminal Heath-Brown/Buchstab blocks, assembles the weighted twin-prime correlation, and derives infinitely many twin primes from that correlation. The conclusion is conditional on the stated Maynard-normalized input and on the normalization made explicit in the paper.