If \( y = y(x) \) is the solution curve of the differential equation \( x^{2} dy + \left( y - \frac{1}{x} \right) dx = 0; \ x > 0 \), and \( y(1) = 1 \), then \( y\!\left( \frac{1}{2} \right) \) is equal to:
\( 3 - e \)
\( 3 + \frac{1}{\sqrt{e}} \)
\( 3 + e \)
\( \frac{3}{2} - \frac{1}{\sqrt{e}} \)