Combined light-UX release NW. Both rebased onto current master (were 96 and
247 behind; net 3-dot diffs applied, byte-identical to PR heads). Both reuse
existing renderers (chat image lightbox / chat CSV table renderer).
Review fix (#4025, Codex): the CSV table preview previously stripped the
workspace Edit affordance .csv had when it fell through to the code preview.
Restored: csv mode is editable, renderCsvPreviewContent caches raw content for
the edit textarea, and saving an edited CSV re-renders the table (not markdown).
Verified the full edit round-trip live + regression test.
Co-authored-by: Rod Boev <rod.boev@gmail.com>
