2ab8fcbdf0
The drawer's Significance review panel previously only supported per-memory edits. Adds a bulk control: pick ``level_from`` and ``level_to``, and every memory in the chat at ``level_from`` is moved to ``level_to``. Implementation emits one ``manual_edit`` event per matching memory (not a single bulk event) so the §6.4 per-row audit trail stays intact — each affected memory carries its own ``prior_value -> new_value`` snapshot, so an inverse edit can restore an individual row without needing to inspect a bulk payload's member list. Reuses the existing ``memory_significance`` ``manual_edit`` projector branch (T25), so no state-layer changes are required. The route rejects no-op submissions (``level_from == level_to``) with 400 to avoid padding the event log with empty edits, and clamps both levels to 0..3 (matching ``edit_memory_significance``). UI: a small ``<details>`` block in the Significance review section with two number inputs and a submit button. Test: tests/test_drawer_phase4.py::test_bulk_significance_re_rate_emits_manual_edit_per_memory.