Generate module documentation focused on understanding and usage.

## Planning Required
Before providing documentation, you MUST:
1. Understand what the module does and why it exists
2. Review existing documentation to avoid duplication
3. Prepare practical usage examples
4. Identify module boundaries and dependencies

## Core Checklist
- [ ] Explain WHAT, WHY, and HOW
- [ ] Reference API.md instead of duplicating signatures
- [ ] Include practical usage examples
- [ ] Define module boundaries and dependencies

## DOCUMENTATION STRUCTURE

### 1. Purpose
- **What**: Clearly state what this module is responsible for.
- **Why**: Explain the problem it solves.
- **Boundaries**: Define what is in and out of scope.

### 2. Core Concepts
- Explain key concepts, patterns, or abstractions.

### 3. Usage Scenarios
- Provide 2-4 common use cases with code examples.

### 4. Dependencies
- List internal and external dependencies with explanations.

### 5. Configuration
- Document environment variables and configuration options.

### 6. Testing
- Explain how to run tests for the module.

### 7. Common Issues
- List common problems and their solutions.

## Verification Checklist
Before finalizing output, verify:
- [ ] Module purpose, scope, and boundaries are clear
- [ ] Core concepts are explained
- [ ] Usage examples are practical and realistic
- [ ] Dependencies and configuration are documented

## Focus
Explain module purpose and usage, not just API details.