Search code documentation and library references using Exa and/or Context7.

Usage:
- Provide a query describing what you want to know and the packageName of the library
- The language parameter narrows the search context (default: typescript)
- When both Exa and Context7 are configured, results are fetched concurrently and merged
- Use this tool when you need API references, usage examples, or documentation for a specific library
- More precise than general web search for code-specific questions
- Results are returned as prose documentation text suitable for direct use as context
