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.
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.
