Update user-facing references from "LangGraph" to "LangChain" per CPK-7186.
The integration label, descriptions, and agent terminology now use "LangChain"
while preserving "LangGraph" for technical references (Platform, Studio, CLI,
StateGraph, code/package names, and API references).
- Rename integration label in integrations.ts, meta.json, integration-grid,
feature-matrix, quickstart-dropdown, and link-validation
- Update ~47 MDX docs: "LangGraph agent(s)" → "LangChain agent(s)"
- Update FAQ, snippets, and learn section references
- Keep URL paths (/langgraph) unchanged for backward compatibility
- Keep all code imports, package names, and LangGraph Platform/Studio/CLI as-is
https://claude.ai/code/session_01JAQ7P3GEeP2bGZtc6V45WY