nx_memindex_emit.nx

nx_memindex_emit.nx -- splice the DERIVED index into a curated markdown file (the MEMORY.md wiring of the conflict-free coindex rail). Sessions APPEND entries to the journal (nx_coindex append -- never editing the shared file); THIS organ is the single writer that regenerates the auto-derived section between whole-line markers: <!-- COINDEX:BEGIN --> ...derived lines (last-write-wins per slug)... <!-- COINDEX:END --> Everything OUTSIDE the markers is preserved BYTE-IDENTICAL (curated sections stay human). FAIL-CLOSED: missing markers -> file untouched. ATOMIC: tmp + fsync + renameat. Serialized under <journal>.lock. EVICTION (2026-07-31, debt 1785558752): the budget gate has always specified a SPLIT -- newest entries stay live in the md block, oldest move into an overflow file COINDEX-OVFL block, nothing is ever lost -- but that capability WAS NEVER IMPLEMENTED. This organ contained zero references to the overflow file, so 4 gate teeth were testing a feature that did not exist, and the whole memindex family read as broken logic when it was in fact an ABSENT CAPABILITY. Built here rather than deleting the teeth (rule 25: build intelligence, never strip features). WHY EVICTION AND NOT REFUSAL: refusing protects the file but leaves the index stale forever, and the harness drops everything past its hard load cliff SILENTLY and TAIL-FIRST. Moving the oldest entries to an overflow file is NOT silent shrinking -- every entry still exists in exactly one of the two blocks (additive, rule 13), and the budget is actually enforced instead of wished for. usage: nx_memindex_emit <journal> <md> [ovfl] [budget] -- legacy: <journal> <md> [budget] The 3rd arg is disambiguated BY CONTENT: all-digits => legacy budget, otherwise the overflow path. That keeps the pre-existing 4th-arg-is-budget contract working (rule 19). With an overflow file the budget measures the DERIVED SECTION; without one it measures the WHOLE composed file and the organ REFUSES rather than write over budget (unchanged behaviour). license_tier: ORIGINAL expect_exit: 0