To what extent is my friend's claim true that Sikhs and Muslims worship the same God, and that there are many similarities between their two faiths? And is what she mentioned about the origin of Sikhism, due to the Mughal persecution of Hindus in India and their coercion into Islam, historically documented?

The Sikhs are an Indian group that emerged in the late 15th century CE. It was founded by "Nanak" who claimed revelation, that he saw the Lord and was commanded by Him to preach, declaring "no Hindus, no Muslims." Nanak attempted to reconcile Islam and Hinduism, and his book mentions some Islamic phrases and terms; however, he established a new religion. He was succeeded by ten teachers, the last of whom was "Gobind Singh," who solidified Sikh enmity towards Muslims, created a special attire for them, and features distinguishing them from others. He also enjoined some religious principles such as letting hair grow freely, wearing an iron bracelet, the turban, placing a comb, and carrying a dagger. Sikhs believe in one God and prohibit idol worship, but they believe in the transmigration of souls and sanctify cows, and they cremate their dead like Hindus. Sikhs suffered persecution from the Mughals and allied with the British. Then, they demanded the state of Punjab as their homeland after their privileges were abolished. Sikhs are known for their enmity and injustice towards Muslims. Sikhs are concentrated in Punjab and some other countries, and their number is estimated at about 15 million people. This religion is considered a pagan, infidel religion, despite its early influence by Islam; however, it strayed from the path and is not considered among the monotheistic religions.