ALTER TABLE osint.exhibit_connections
  ADD COLUMN tag_position_percent SMALLINT NOT NULL DEFAULT 50
    CHECK (tag_position_percent BETWEEN 0 AND 100),
  ADD COLUMN tag_lateral_offset SMALLINT NOT NULL DEFAULT 0
    CHECK (ABS(tag_lateral_offset) <= 10 + ROUND((100 - tightness) * 0.6));

COMMENT ON COLUMN osint.exhibit_connections.tag_position_percent IS 'Position of the relation tag along its red thread, measured from the source exhibit';
COMMENT ON COLUMN osint.exhibit_connections.tag_lateral_offset IS 'Signed perpendicular tag displacement, limited by thread tightness';
