Canva Inc. launched an employee stock sale at a valuation of $42 billion, marking a significant leap in value for the Australian design software startup that’s betting on artificial intelligence for growth.Employees can sell stock to new and existing investors, including Fidelity Management & Research Co. and JPMorgan Chase & Co.’s asset management arm, Canva said in a statement on Wednesday. The offer boosts Canva’s valuation more than 30% — it was valued at $32 billion in 2024....