If \( \int_{0}^{\pi/4} \frac{\sin^{2} x}{1 + \sin x \cos x} \, dx = \frac{1}{a} \log_{e}\!\left(\frac{a}{3}\right) + \frac{\pi}{b\sqrt{3}} \) where \( a, b \in \mathbb{N} \), then \( a + b \) is equal to __________.