Carry Schedule E line 32 by entity on the US PUF donor; retire the S-corp exact-zero universe

changelog.d/1258-puf-schedule-e-entity-split.changed.md

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+The US PUF donor now carries the partnership and S corporation shares of Schedule E line 32 as separate leaves (`partnership_income` = E25940 + E25980 − E25920 − E25960 − E26110; `s_corp_income` = E26170 + E26190 − E26160 − E26180 − E26100, from the TY2015 source rows). Previously the whole line-32 total sat in `partnership_income` and `s_corp_income` was an exact-zero universe. Their sum equals E26270 within the booklet's per-field rounding, and the passive subset is byte-identical. The exact-zero machinery is retired: the stacked-spine materializer and its whole-pool doctrine, the late-transfer exclusion, the pool's `primary_puf_exact_zero_universe` provision, the donor's zero alias and the fiscal-refresh degenerate-input exclusion. `s_corp_income` is now a PUF-clone primary output that the late ACS transfer carries to native rows. SOI Table 1.4's partnership and S corporation net income/loss legs bind each entity's own leaf once the feed carries them (microcosm#1258).