nx_map.nx

map.nx -- Robin-hood hashmap with FNV-1a (Phase G8). Research: Celis 1986 (robin-hood hashing), Noll 1991 (FNV-1a). Robin-hood hashing levels probe-distance variance so worst-case lookup stays close to average. FNV-1a is simple, fast, and good enough for integer + byte-string keys we'll hash in practice. Specialised to (i64, i64) entries for now — generalises to Map<K, V> once parse.nx's multi-param generics ship. Use cases: * Symbol tables in nxasm/nxld (name-hash → offset) * Route tables in runtime/http.nx (path-hash → handler id) * JSON object parse tables (key-hash → value index) * Config stores (key-hash → value) Open addressing with linear probing; load-factor cap 0.75; power- of-2 bucket count for AND-mask indexing. Deletions use tombstone markers (so subsequent probes still find displaced entries).