-- Migration 014: stop encoding diagnostics and lifecycle records as scratchpad.
-- Historical rows stay immutable; projections recognize their legacy payload types.
PRAGMA foreign_keys = OFF;
BEGIN IMMEDIATE;

CREATE TABLE events_v2 (
    seq INTEGER PRIMARY KEY AUTOINCREMENT,
    session_id TEXT NOT NULL REFERENCES sessions(id),
    kind TEXT NOT NULL CHECK(kind IN (
        'input','scratchpad','context.receipt','model.usage','tool.result','turn.failed','turn.outcome',
        'execution.started','execution.completed','execution.unknown',
        'local.sent','delivery.held','kernel.reset','session.waited',
        'session.woke','hooks.activated','kernel.placement','remote.repair',
        'runtime.slice','runtime.task_paused','lcm_frontier',
        'frontier.install_failed','frontier.selected','frontier.deferred',
        'frontier.abandoned','frontier.quiet','orientation.adopted',
        'maintenance.attempt_completed','maintenance.attempt_failed'
    )),
    source_key TEXT,
    payload TEXT NOT NULL CHECK(json_valid(payload)),
    created_ms INTEGER NOT NULL CHECK(created_ms >= 0),
    UNIQUE(session_id, source_key)
) STRICT;

INSERT INTO events_v2 (seq, session_id, kind, source_key, payload, created_ms)
SELECT seq, session_id, kind, source_key, payload, created_ms FROM events;

DROP TABLE events;
ALTER TABLE events_v2 RENAME TO events;

CREATE INDEX events_session_order ON events(session_id, seq);
CREATE TRIGGER events_no_update BEFORE UPDATE ON events BEGIN
    SELECT RAISE(ABORT, 'historical events are immutable');
END;
CREATE TRIGGER events_no_delete BEFORE DELETE ON events BEGIN
    SELECT RAISE(ABORT, 'historical events are immutable');
END;

CREATE TEMP TABLE _orphan_guard (reason TEXT CHECK (reason IS NULL));
INSERT INTO _orphan_guard (reason)
SELECT 'orphaned ' || "table" || ' row ' || rowid || ' via fk ' || fkid || ' -> parent ' || parent
FROM pragma_foreign_key_check;
DROP TABLE _orphan_guard;

PRAGMA user_version = 14;
COMMIT;
PRAGMA foreign_keys = ON;