Schema Design: Use triple quotes for descriptions

Use triple-quote syntax (`"""description"""`) for field and type documentation, not `#` symbols.

Rationale: Triple quotes are parsed as descriptions and appear in introspection and documentation tools. Hash comments are ignored by the parser and invisible to consumers.

**Example:**

Prefer:
```
"""
The business name
"""
name: String
```

Not:
```
# The business name
name: String
```