What is the primary purpose of Chapter 1 of the Sai Satcharitra, and which deities are invoked at the beginning?

Chapter 1 of the Sai Satcharitra, titled 'Mangalacharan,' serves as a series of auspicious invocations to ensure the obstacle-free completion of the book. As detailed in the chapter, the author begins by offering salutations to several divine figures for the removal of all obstacles. First, there is a bow to Lord Ganesha, the destroyer of obstacles, who is also identified with Sai himself. This is followed by an invocation to Goddess Saraswati, the goddess of speech and knowledge, asking for her grace to write the book. The chapter also includes salutations to the trinity of Brahma, Vishnu, and Shankar, who represent creation, preservation, and destruction, as well as the family deity, Narayana.