Run Gauntlet Challenge

Present challenges from the knowledge base and evaluate answers.

Steps

1. Load state: read .gauntlet/knowledge.json and developer progress

2. Check for pending challenge: if .gauntlet/state/pending_challenge.json exists, evaluate the developer's most recent message as an answer before generating a new one

3. Generate challenge: use adaptive weighting to select a knowledge entry and challenge type

4. Present challenge: show the question with context