-- +goose Up
-- Instance integrity: stage position unique, frozen task metadata columns

CREATE UNIQUE INDEX IF NOT EXISTS uq_stage_instance_position
    ON project_stage_instances (workflow_instance_id, position)
    WHERE position > 0;

ALTER TABLE project_doc_task_instances
    ADD COLUMN IF NOT EXISTS executor_key TEXT NOT NULL DEFAULT '',
    ADD COLUMN IF NOT EXISTS template_version INT NOT NULL DEFAULT 0,
    ADD COLUMN IF NOT EXISTS quality_gate_key TEXT NOT NULL DEFAULT '';

-- +goose Down
ALTER TABLE project_doc_task_instances
    DROP COLUMN IF EXISTS quality_gate_key,
    DROP COLUMN IF EXISTS template_version,
    DROP COLUMN IF EXISTS executor_key;

DROP INDEX IF EXISTS uq_stage_instance_position;