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.
E4's pack-fn source-pin was incomplete: an imported pack function's
fixed-prefix (non-pack) parameter types were resolved in the CALLER's
module, so a param whose type is bare-visible only in the pack fn's own
module was wrongly rejected with "type 'X' is not visible" — even though
the equivalent plain fn (typed via the source-pinned call-arg path) ran
fine.
Two sites in the pack-mono path re-resolved the fixed-prefix param type
in the caller's context:
- lowerPackFnCall: the call-site arg-typing pass (to contextually type
the arg from its param) — fires first.
- monomorphizePackFn: the body parameter binding, after the caller
source was restored from the signature build.
Both now resolve via resolveParamTypeInSource(fd.body.source_file, &p),
pinning to the pack fn's defining module — matching the already-pinned
signature build, the body lowering, and the cross-module call-arg typing
sites. The call-site arg itself is still lowered AFTER, in the caller's
context (issue 0106).
Regression: examples/0544-packs-imported-pack-fn-fixed-param-source-pin
(main -> lib -> dep; `Needs` two flat hops away, never named in main).
Fails pre-fix with "type 'Needs' is not visible"; passes after. A control
plain fn in the same lib already ran, isolating the pack-mono path.
