Hojun-Cho
36be9f469d
A spread whose source was not a local ident fell PAST the spread arm: cstage continued into the single-value stores with the N_SPREAD node (garbage store), wwstage silently SKIPPED the value entirely — a silent, cs!=ww-divergent miscompile (append(ys, f()...): cs exit 0 / ww exit 144, want 3), reachable for every element kind and predating #34 for scalars. Both stages now rule-7 loud-stop the shape (deferred, task #37). Also pins the widener's already-tagged single-value source path (tagged_ident_src row, i64 + bool members) and adds the spread_call_loudstop BUILD_FAIL row — test 800 is now 15 rows / 43 fixtures.