Weak models emit a table as a header row followed by FLAT row-indexed sibling
cells (R1 Client Cell, R1 Visit, …, R2 Client Cell, …) that render stacked
vertically with full-width status bars. table_repair::regroup_flat_table_rows
groups them into Table→Row→Cell with header-aligned column widths. Detection is
narrow and never guesses (adversarial review caught heuristic-header /
chunk-of-N over-firing on toolbars/feeds): it requires an explicit table header
AND every cell to carry an R{n} row index, aborting on any ragged/ambiguous run.
ReplaceSubtree allocates a fresh root id, so the structural restructures
(app_shell + table_repair) ran via a new apply_root_transform helper that
returns the current root id; run_cleanup_passes threads it into the subsequent
per-root passes instead of the stale id (which they'd otherwise no-op on).
7956595853