VibeLearn silently watches your Claude Code sessions, extracts the concepts you encounter while building, and turns them into personalized quiz questions — so you actually retain what you learn. After each session, run `vl quiz` to review with adaptive spaced repetition across 7 question formats (multiple choice, spot the bug, code reading, fill in the blank, open-ended, true/false, ordering). Difficulty adjusts automatically: 3 correct answers in a row promotes you to the next level, one wrong answer drops you back. Senior-level open-ended answers are evaluated by a 5-dimension AI rubric.