General upper support of the source-faithful layer.
If the Lemma 7.1 lower outer cutoff fails, the recursively remaining layer vanishes.
Legal-domain recurrence: the source carrier may be extended to every
supported p < z. The odd-index upper cutoff is automatic from z^3 ≤ D;
the omitted lower-cutoff terms vanish by the preceding support lemma.
Index two: no parity-domain hypothesis is needed.
Index three: z^3 ≤ D is exactly the legal odd-domain assumption making
Suzuki's extra outer upper cutoff automatic.
Exact induction invariant for the full bridge: at layer n, z^n ≤ D
propagates to p^(n-1) ≤ ceil(D/p) for every supported outer prime p < z.
This simultaneously makes every odd source upper cutoff automatic.
Index two closes under the exact even legal-domain hypothesis.
Index three closes under the exact odd legal-domain hypothesis.
Consequently the source-faithful parity sum agrees with the renamed §14
extended sum on the uniform legal domain z^N ≤ D.