nx_commons_ledger_e2e_gate.nx

nx_commons_ledger_e2e_gate.nx -- PERSIST -> RELOAD -> AGGREGATE against the real seg-store. WHY THIS EXISTS: nx_commons_ledger_gate proved the aggregator over rows held in memory. That is NOT evidence that the ledger survives a restart, and I nearly let "the ledger persists" stand on it. AN AGGREGATOR PROVEN OVER AN IN-MEMORY FIXTURE HAS PROVEN NOTHING ABOUT DURABILITY. Here the rows go through sts_seed / sts_append_row into a real plane, and come back through sts_load_honest into a FRESH buffer that never saw the write side. sts_load_honest, not sts_load: it reports truncation. A bounded read that silently returns a prefix is how this estate once served a log's HEAD as its TAIL and declared a live guard dead for 12.5 days. If the plane outgrows the buffer this gate must say so, not quietly aggregate half a ledger. ⚠ sts_seed RETURNS A COUNT -- positive is success, not failure. Throwaway prefix by construction; it never touches a production plane. license_tier: ORIGINAL expect_exit: 0