Update the 2026-06-21 approved spec with the post-SP27 reality:
store.py grew 2,412 → 2,995 LOC. Three new top-level symbols
(dashboard_kpis, _claim_state_str, check_matched_pair_drift) get
slotted into the new kpis.py and claim_detail.py. Three private
helpers (the original _claim_status_from_validation + the newly-
discovered _persist_835_remit and _remittance_835_row) are re-
exported from the facade to preserve the 4 test files that
import them. Branch bumped to sp21-store-split per SP-N convention.
All previously-locked Decisions are preserved verbatim.
Nora
fbe7b2358d