What is the primary purpose and structure of the opening chapter of the Sai Satcharitra?

Chapter 1 of the Sai Satcharitra, titled 'Mangalacharan', serves as a series of auspicious invocations. As explained within the chapter, this practice is performed at the beginning of a task to ensure its completion without obstacles and to gain the favor of deities. The purpose is the fulfillment of the desired goal, which is the successful writing of the book. The structure involves offering salutations to Lord Ganesha, Goddess Saraswati, the divine trinity of Brahma, Vishnu, and Shankar, the family deity, and finally, Sadguru Sainath himself, who is identified as the embodiment of all these divine forms.