Spell Teach

## Summary

**Dedicated entry point for learning the concepts behind the spells.** Each spell applies an established idea from a real field — programming, education, UX design, documentation theory, or operations research. This command explains what the concept is, where you already encounter it, and how the spell applies it.

**Arguments:** `$ARGUMENTS` (optional) - Spell name to explain (e.g., "idiomatic", "doc-audit")

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## Process

### Step 1: Parse Arguments

**If `$ARGUMENTS` is empty:**
Output a concept overview for all spells:

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