-- The durations the core's bounds are set from (novox/hq to-be 45 Phase 0).
--
-- Every watchdog of the core's signals table has a bound — how long a machine may take to report
-- after a send, how long it may be silent, how long a plan's tier or a build may take — and a bound
-- guessed is a condition that cries wolf or one that never fires. So the controller records each
-- duration as it is observed, and Phase 1 sets the bounds from what was recorded:
--
--   apply          a declaration sent → the machine's first report of that declaration, per machine
--   heartbeat-gap  one word from a machine → the next, per machine
--   plan-tier      a plan entering a tier → leaving it, per repository
--   build          a build asked → its outcome heard, per module
--
-- One row per thing measured: `ref` names it (the send, the earlier word, the plan's tier, the
-- build), so a report repeated by a reconcile is not a second measurement. Kept a month; read
-- through `durations`.
create table duration (
    kind     text        not null,
    subject  text        not null,
    node     text        not null default '',
    ref      text        not null,
    started  timestamptz not null,
    took_ms  bigint      not null,
    detail   text        not null default '',
    recorded timestamptz not null default now(),
    primary key (kind, subject, ref)
);

create index duration_by_kind on duration (kind, recorded);

-- When a plan entered the tier it is at, so leaving it measures the tier.
alter table release_plan add column tier_entered timestamptz;