0056 shipped in #7906 and is checksum-frozen, so restore it byte-for-byte and
move this branch's columns, index and root-index drop to 0057. 0057 sets
lock/statement budgets like 0049, admits a concurrent prebuild of
idx_event_mentions_scope_received, and validates its catalog shape. Parity of
the altered tables is checked against a migrated database.
Signed-off-by: hMB2 <0400eb0da32afbbf16cdd1dee6ffd243587e8f3d6a2823fe7dfa95d16b002b7d@buzz.block.builderlab.xyz>