Adult learning & knowledge management meta-router — 12 cognitive science-based frameworks (Zettelkasten, PARA/Second Brain, Evergreen Notes, Spaced Repetition, Active Recall, Feynman Technique with AI-as-feedback-channel workflows, Interleaving, Deliberate Practice, Chunking, Deep Work, Pomodoro, Metalearning). Based on Ebbinghaus, Roediger-Karpicke, Bjork, Ericsson research. Korean learner context (수능/CSAT, 공무원 civil service exams, CPA, 회독 repeated-reading culture). Invoke /learn.