Twitter Inc sued Elon Musk on Tuesday for violating the US$44 billion deal to buy the social media platform and asked a Delaware court to order the world’s richest person to complete the merger at the agreed US$54.20 per Twitter share, according to a court filing. “Musk apparently believes that he – unlike every other party subject to Delaware contract law – is free to change his mind, trash the company, disrupt its operations, destroy stockholder value, and walk away,” the lawsuit said. The lawsuit sets in motion what promises to be one of the biggest legal showdowns in Wall…