CREATE TABLE IF NOT EXISTS audit_events (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    event_type TEXT NOT NULL,
    allocation_id INTEGER NULL REFERENCES allocations(id),
    pool_id INTEGER NULL REFERENCES pools(id),
    actor TEXT NOT NULL DEFAULT 'local',
    details_json TEXT NOT NULL,
    created_at TEXT NOT NULL
);

CREATE INDEX IF NOT EXISTS idx_audit_events_allocation_id ON audit_events(allocation_id);
CREATE INDEX IF NOT EXISTS idx_audit_events_pool_id ON audit_events(pool_id);
CREATE INDEX IF NOT EXISTS idx_audit_events_created_at ON audit_events(created_at DESC);