skill-tree: finding the Claude behaviors you systematically avoid

After months of daily Claude Code use, I ran my session history through Anthropic's AI Fluency Index taxonomy and found I'd triggered 8 of the 11 observable behaviors — but three had zero occurrences. Not low. Zero. That's the problem skill-tree is built around. It's not hard to get faster at the things you already do. The trap is that fluency gains feel real even when you're just deepening the same ruts. What it does skill-tree installs as a Claude Code plugin, reads your session history, and c