Move examples/*.sx and their expected/ snapshots into per-category
subfolders (examples/<category>/...). Folder = leading filename token,
with ffi-objc/ffi-jni kept whole; filenames are unchanged. The corpus
runner and LSP sweep now discover each category's expected/ dir, while
issues/ stays flat. Example 1058's repo-root-relative companion import
is made file-relative. Path strings embedded in 164 snapshots were
regenerated (path-only changes). Test-layout docs in CLAUDE.md updated.
set_nonblocking (C-variadic fcntl), errno via __error (darwin; C3
selects per-OS), and accept_nb/read_nb/write_nb returning a typed
SockErr — WouldBlock / Closed / Fault — so readiness-loop callers never
parse -1/errno pairs. EINTR retries internally; accept_nb skips
ECONNABORTED. Adds connect, shutdown, socketpair, AF_UNIX, SHUT_*.
examples/1630 pins the result algebra on a socketpair and a nonblocking
TCP listener (WouldBlock on empty backlog, accept after loopback
connect); verified under sx run AND sx build. The .ir snapshot regen is
mechanical: new std decls shift @str/@tag.str numbering and grow the
type table (179 -> 185).
A named #import c unit declared inside an aliased module sits two
namespace levels deep in the merged tree; the one-level walk (the
extractLibraries/0130 pattern in c_import form) never collected it,
so the unit silently never compiled and its symbols resolved from
whatever process image carried the same names — surfaced by C4's
sqlite migration, where only the version pin could tell the OS copy
from the vendored one.
