-- Migration 015: the instruction header of a transcript is durable state.
--
-- A pinned header and the revisions observed after it are prompt-bearing records, so they
-- belong in the event log with the other history rather than in a side table: replay has to
-- reach the same request bytes, and the immutability triggers already protect that.
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',
'prompt.header','prompt.revision'
)),
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 = 15;
COMMIT;
PRAGMA foreign_keys = ON;