chore: restructure lambda-query skill with detailed reference docs

Break the single monolithic SKILL.md into a concise overview with
three focused reference documents:
- references/core-api.md: full core API with types, edge cases, events
- references/react-bindings.md: all hooks, components, and React types
- references/testing-patterns.md: test setup, patterns, and gotchas

Author: ConsoleTVs