plano/demos/use_cases/langchain/gateway_test.rest

### Weather via Plano (8001)
POST http://localhost:8001/v1/chat/completions
Content-Type: application/json

{
  "model": "openai/gpt-4o-mini",
  "stream": true,
  "messages": [
    { "role": "user", "content": "What's the weather in Lahore?" }
  ]
}

### Flight via Plano (8001)
POST http://localhost:8001/v1/chat/completions
Content-Type: application/json

{
  "model": "openai/gpt-4o-mini",
  "stream": false,
  "messages": [
    { "role": "user", "content": "Find flights from Seattle to Atlanta." }
  ]
}

### Multi-intent via Plano (8001)
POST http://localhost:8001/v1/chat/completions
Content-Type: application/json

{
  "model": "openai/gpt-4o-mini",
  "stream": false,
  "messages": [
    { "role": "user", "content": "What's the weather in Tokyo this weekend, and any direct flights to Sydney?" }
  ]
}