Batch 2 of the test-arch reframe. These three are codegen-SHAPE tests,
not data-row tests: each subject is a distinct node shape (N_IDENT
module-global read; chained N_INDEX m[i][k]; index-base node-kind). A
[N]struct row-table would interpose its own N_INDEX/N_DOT lowering and
mask the shape under test, so each uses per-shape @test fns with direct
asserts (rob-ratified rule: table where the row is data, per-fn where
the row is a codegen shape). Lossless from the matching
989_{gunsigned,chainidx,idxarg}_run.c; additive (C kept); both stages green.
Proof-of-path for the test-arch reframe: pure-behavior rows become
in-language @test row-tables run by `ww test`, reserving C drivers for
the two irreducible jobs (byte-id + bootstrap). 110_uniesc's 6 value
rows become [N]struct row-tables in a new test/lang/ tree; the trailing
.wwi round-trip stays in C as external-observer residue. Additive — the
C rows are kept; de-dup and make-rewiring land at fold 6 (task #12).
Green on both stages.
