Cognitive therapy software for improving cognitive function for patients with mild cognitive impairment (SB‐DEX): A multicenter, prospective, comparative, randomized, independent rater‐blind, superiority, pivotal clinical trial to compare the safety and efficacy of the Cognitive therapy software ‘SUPERBRAIN DEX’ for improving cognitive function with a control group for patients with mild cognitive impairment (ClinicalTrials.gov ID NCT06264557)