-- Enforce valid normalized coordinate ranges for annotation bounding boxes.
-- x and y must be within [0, 1]; width and height must be at least 1% of the
-- document dimension and at most 100%.
-- Consistent with the application-layer minimum draw threshold (0.01).
ALTER TABLE document_annotations
    ADD CONSTRAINT chk_annotation_bounds
        CHECK (
            x >= 0 AND x <= 1 AND
            y >= 0 AND y <= 1 AND
            width >= 0.01 AND width <= 1 AND
            height >= 0.01 AND height <= 1
        );
