This reverts commit 9e827685f2 (#136424). It landed before the announced
October 15, 2026 date for holographic leaving core; it re-lands on or after
that date. Restores plugins/memory/holographic and its tests/docs.
This reverts commit 9e827685f2 (#136424). It landed before the announced
October 15, 2026 date for holographic leaving core; it re-lands on or after
that date. Restores plugins/memory/holographic and its tests/docs.