Can you summarize the key deities invoked at the beginning of the Sai Satcharitra and the author's ultimate declaration about Sai?

The beginning of the Sai Satcharitra, as detailed in Chapter 1, is marked by a series of auspicious invocations, or 'Mangalacharan'. The author offers salutations to several deities to ensure the obstacle-free completion of the book. These include Lord Ganesha, the destroyer of obstacles; Goddess Saraswati, the goddess of speech and knowledge; the trinity of Brahma, Vishnu, and Shankar; and the family deity, Narayana. The central theme running through these invocations, as Chapter 1 reveals, is the author's profound belief that Sai Baba is the non-dual embodiment of all these deities, calling him the boat to cross the river of worldly existence.