-- Folds research into loops as a "kind" of loop. Two kinds exist:
--
--   'exec'     — today's behavior. Each iteration runs the coordinator
--                task_template (optionally prepended with a research
--                artifact + focus instructions for INT-consumption
--                loops).
--   'research' — the fire runs the research pipeline against a bound
--                topic config, appending a versioned research_outcomes
--                row each time. Used for nightly paper-survey loops
--                (D1 answer: every runnable thing is a loop; even a
--                one-shot topic gets its own kind='research' loop with
--                initial_burst=1).
--
-- Default 'exec' + CHECK constraint keeps every existing row valid.
-- The paired research + coding pattern (nightly research produces
-- outcome, coding loop wakes on on_artifact_update to consume next INT)
-- composes two loops of different kinds sharing a source topic id.
ALTER TABLE loops
    ADD COLUMN kind TEXT NOT NULL DEFAULT 'exec'
        CHECK (kind IN ('exec', 'research')),
    -- Countdown for the triggers.initial_burst quota. On create_loop
    -- we enqueue the first iteration inline and set this to burst-1;
    -- on each completion the topology_worker checks and, when > 0,
    -- enqueues the next iteration + decrements. Once it hits 0 the
    -- burst is exhausted (further iterations happen only through
    -- cron / webhook / on_completion / on_artifact_update).
    ADD COLUMN initial_burst_remaining INT NOT NULL DEFAULT 0;

CREATE INDEX loops_kind_source_idx
    ON loops (kind, source_research_topic_id)
    WHERE source_research_topic_id IS NOT NULL;

-- Fast lookup for the on_artifact_update hook: given a topic_id, find
-- all exec-kind loops bound to it with the trigger enabled.
CREATE INDEX loops_on_artifact_update_idx
    ON loops (source_research_topic_id)
    WHERE source_research_topic_id IS NOT NULL
      AND (triggers ->> 'on_artifact_update')::boolean = true
      AND enabled = true;