Hojun-Cho
532b0a88ae
io.error grows errors.invalid (ref/hare/io/types.ha:11 spreads ...errors::error, which includes it; Hare's memio seek returns it on out-of-bounds, stream.ha:134-136) — appended last so existing member tags stay put; no exhaustive io.error matches exist in lib. seekfn mirrors ref/hare/memio/stream.ha:122-140 over the flat header, shared by fixed/dynamic/dynamicfrom (Hare wires the same seek into both vtables). The io.off-vs-i64 arithmetic runs on an i64 copy: cstage binop typing is nominal on aliases, wwstage accepts (filed, ww-core #54). 791's stream_seek_unsupported row re-pins st_seek's void-arm on a hand-built seekerless vtable: its old premise (memio wires no seeker) is retired by this commit; memio seek success is pinned by memiotest. w6c/wwdump main.combined.ww regen'd: they embed lib/io + lib/memio (the freshness gates are blind to this — embedded-source discipline); w6a/w6l/ww don't embed io, verified untouched.