If the tangent at a point \( P \) on the parabola \( y^{2}=3x \) is parallel to the line \( x+2y=1 \) and the tangents at the points \( Q \) and \( R \) on the ellipse \( \dfrac{x^{2}}{4}+\dfrac{y^{2}}{1}=1 \) are perpendicular to the line \( x-y=2 \), then the area of the triangle \( PQR \) is:
