-- Append-only event log of coordinator-issued reorders on a
-- research-bound loop. Whenever a run's coordinator emits
--   REORDER: INT-05 before INT-04 because prereq X is unmet
-- (or any `REORDER: <text>` line in the run's final output), the
-- topology_worker completion hook parses it and appends a
--   {iteration, run_id, text, ts}
-- object to this array. The loop card can then surface a mini-timeline
-- of when the plan was adjusted and why — useful when the reviewer
-- wants to understand why P0 items landed out of order.
--
-- JSONB rather than a separate table so the loop row carries its own
-- history — reads are already fast (loops list <10ms) and a
-- per-iteration event log lives naturally alongside consumed_int_ids +
-- current_int_index. If the log grows huge we can promote to a
-- dedicated table later.
ALTER TABLE loops
    ADD COLUMN reorder_events JSONB NOT NULL DEFAULT '[]'::jsonb;