Closes G9.
DELETE on a folder now flips is_trashed on every descendant folder
and file under it in a single CTE pipeline (lpath <@ root.lpath
covers the whole subtree via the GiST index). Previously only the
root row was flipped — descendants stayed live, directly addressable
via their full path, and confused desktop-sync tree walks that
expected the parent-collection 404 to imply the children were gone
too.
restore_from_trash mirrors the cascade: descendants where the
original_*_parent_id column is NULL are the ones we cascade-trashed,
so they get cascade-restored too. Descendants that were independently
trashed before the parent went to trash have original_*_parent_id
set, so they stay in trash and remain visible as top-level entries
in storage.trash_items.
No schema migration needed — both original_parent_id (folders) and
original_folder_id (files) were already nullable and already encoded
'where this came from when it was independently trashed'; using NULL
as the cascade-marker reuses that existing distinction cleanly.
Test G9 flipped from KNOWN BUG to assert every descendant 404s after
the parent DELETE; new G9b proves the inverse cascade by restoring
the trashed root and verifying every descendant comes back at its
original path.
Edouard Vanbelle
e2702ac673