-- Structured mission activity: what an agent actually DID, as data.
--
-- Until now the World could show a mission's shape (phases, status, who is on
-- which station) but nothing about the work itself. The detail existed only as
-- prose in `checkpoint.log` and agent output, where a tool name is
-- indistinguishable from an agent *talking about* a tool — so it was never
-- parsed, deliberately. This table is the structured channel that replaces it.
--
-- `run_events` could not be reused: 0003 declares `run_id REFERENCES
-- agent_runs(id)`, and mission phases insert into `topology_runs`. Those are
-- independent id spaces, so every write would have been an FK violation.
CREATE TABLE IF NOT EXISTS mission_events (
    id          BIGSERIAL PRIMARY KEY,
    mission_id  UUID NOT NULL REFERENCES missions(id) ON DELETE CASCADE,
    -- No FK. `mission_phases` rows survive, but a phase that loops is re-run
    -- and this column is only ever read as a grouping key.
    phase_id    UUID,
    -- Deliberately NO FK, and this is the load-bearing decision in the file:
    -- `phase_runner` DELETEs the `topology_runs` row on every retry. With a
    -- cascading FK, a phase's whole history would vanish the moment it retried
    -- — silently, since a cascade is not an error. The id is kept as a plain
    -- correlation value.
    run_id      UUID,
    -- The platform agent, when there is one. NULL for a microVM phase, which
    -- has no platform agent at all — that is the truth, not missing data.
    agent_id    UUID,
    -- phase.started | phase.completed | tool.call | file.touch
    -- | finding.raised | benchmark.delta
    kind        TEXT NOT NULL,
    -- The tool name, or the file path — whatever the event is *about*.
    target      TEXT,
    detail      JSONB NOT NULL DEFAULT '{}'::jsonb,
    created_at  TIMESTAMPTZ NOT NULL DEFAULT now()
);

-- The World reads by mission, newest last, and by phase for the per-phase cap.
CREATE INDEX IF NOT EXISTS mission_events_mission_idx
    ON mission_events (mission_id, id);
CREATE INDEX IF NOT EXISTS mission_events_phase_idx
    ON mission_events (phase_id, id);
-- The retention sweep in `mission_gc` scans by age.
CREATE INDEX IF NOT EXISTS mission_events_created_idx
    ON mission_events (created_at);