feat: mentor skill

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

README.md

@@ -13,6 +13,10 @@ Every module follows the same beats: Observe, Predict, Spec, Build, Name it, Exp
 - **Designer path**: read the lessons and scenarios, predict outcomes, and reason about the design.
 - **Builder path**: also make the tests pass in your own engine.
 
+## Mentor path
+
+Prefer a Socratic partner? Install the [mentor skill](mentor/README.md) and let your AI agent guide you without writing your code.
+
 ## Two tracks
 
 Builder path exercises exist in **Rust** and **TypeScript**. Both tracks have identical test names, matching the scenarios in each module's `scenarios.md`.