[Bug]: misleaing desc runtime.graphql.depth-limit

## Misleading
Doesn’t document the meaning of null (infinity) or -1 (remove limit) that the CLI references.
> "Maximum allowed depth of a GraphQL query."

Start by locating the CLI reference or configuration definition for runtime.graphql.depth-limit mentioned in the issue. Update the setting description to explain that null means infinity and -1 removes the limit; done means the documented wording matches the CLI behavior.

Written by the indexing model from the issue text.