ALTER TABLE ias_long_term_memories ALTER COLUMN created_at TYPE TIMESTAMPTZ USING created_at AT TIME ZONE 'UTC', ALTER COLUMN updated_at TYPE TIMESTAMPTZ USING updated_at AT TIME ZONE 'UTC', ALTER COLUMN deleted_at TYPE TIMESTAMPTZ USING deleted_at AT TIME ZONE 'UTC', ALTER COLUMN created_at SET DEFAULT NOW(), ALTER COLUMN updated_at SET DEFAULT NOW(); ALTER TABLE ias_context_sessions ALTER COLUMN started_at TYPE TIMESTAMPTZ USING started_at AT TIME ZONE 'UTC', ALTER COLUMN last_message_at TYPE TIMESTAMPTZ USING last_message_at AT TIME ZONE 'UTC', ALTER COLUMN ended_at TYPE TIMESTAMPTZ USING ended_at AT TIME ZONE 'UTC', ALTER COLUMN started_at SET DEFAULT NOW(), ALTER COLUMN last_message_at SET DEFAULT NOW(); ALTER TABLE ias_context_messages ALTER COLUMN created_at TYPE TIMESTAMPTZ USING created_at AT TIME ZONE 'UTC', ALTER COLUMN created_at SET DEFAULT NOW(); ALTER TABLE ias_context_summaries ALTER COLUMN started_at TYPE TIMESTAMPTZ USING started_at AT TIME ZONE 'UTC', ALTER COLUMN ended_at TYPE TIMESTAMPTZ USING ended_at AT TIME ZONE 'UTC', ALTER COLUMN created_at TYPE TIMESTAMPTZ USING created_at AT TIME ZONE 'UTC', ALTER COLUMN created_at SET DEFAULT NOW();