Add framework quickstarts to TypeScript client examples

[jdrhyne]

Summary

• add a Framework Quickstarts section in the root README
• add framework integration sketches in examples/src/ for:
  • OpenAI Agents (framework_openai_agents.mjs)
  • LangChain (framework_langchain.mjs)
  • CrewAI scope note for TypeScript users (framework_crewai_scope.md)
• update examples/README.md with:
  • framework run commands
  • optional install command for framework dependencies
  • syntax-check commands
• align framework example asset paths with documented cd examples execution flow
• execute LangChain tool_calls explicitly so the DWS action actually runs
• replace nonexistent client.redact(...) usage with supported createRedactionsPreset(...)

Validation

• node --check examples/src/framework_openai_agents.mjs
• node --check examples/src/framework_langchain.mjs
• codex review --disable apps -c model_reasoning_effort='"low"' --uncommitted