Get Mesh From Batch: `index` becomes `selection`, accepting an index ("2",
"-1", clamped) or a Python slice ("1:5", ":3", "::2", "-3:", self-clamping).
Output is now a TRIMESH list (a single index yields a batch of one, which
maps identically downstream). Parser covered by exhaustive standalone tests
(indices, negative, out-of-range, all slice forms, error cases).
Preview Mesh Multi (Batch) deleted (node, widget JS, registration): the
autogrown Preview Mesh Multi subsumes it -- batch-accepting sockets, better
auto grid, client-side dims, wipe layout, full-list passthrough vs its silent
rows*cols truncation. workflows/extract_connected_components.json still
references the deleted node; CI breakage accepted by user, workflow to be
migrated separately.
PozzettiAndrea
a939374186