HTTP请求执行服务

- `method` (string, required) — HTTP method (GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS)
- `url` (string, required) — Target URL beginning with http:// or https://
- `headers` (object, optional) — Optional HTTP headers as a dict of string key/value pairs. Omit to send no custom headers.
- `params` (object, optional) — Optional query parameters as a dict; appended to the URL as ?key=value pairs. Omit to send no query string.
- `json_body` (any, optional) — Optional JSON request body (any JSON-serializable value). Mutually exclusive with `body`. Omit for requests with no body.
- `body` (string, optional) — Optional raw string request body. Mutually exclusive with `json_body`. Omit for requests with no body.
- `timeout_seconds` (number, optional, default: 30.0) — Read timeout in seconds for the HTTP request. Defaults to 30.0s if omitted. Increase for slow endpoints.
- `follow_redirects` (boolean, optional, default: true) — Whether to follow HTTP 3xx redirects automatically. Defaults to true if omitted.
- `max_response_chars` (integer, optional, default: 50000) — Maximum response body characters or bytes to return. Defaults to 50000 if omitted. Increase to retrieve larger responses.

{
  request: {
    method: string;
    url: string;
    headers: { [key: string]: string };
    params: { [key: string]: any };
    timeout_seconds: number;
    follow_redirects: boolean;
    max_response_chars: number;
  };
  response: {
    url: string;
    status_code: number;
    reason_phrase: string;
    headers: { [key: string]: string };
    elapsed_ms: number;
    body: {
      kind: string;
      content: string;
      truncated: boolean;
      original_length: number;
      json: any | null;
    };
  };
}

// Success
{
  "success": true,
  "statusCode": 200,
  "retriable": false,
  "retry_after_seconds": null,
  "error": null,
  "data": { ... }
}

// Error
{
  "success": false,
  "statusCode": 400,
  "retriable": false,
  "retry_after_seconds": null,
  "error": { "code": "VALIDATION_ERROR", "message": "{description}", "details": {} },
  "data": null
}

Format: https://{host}/{path}?{query}
Example: https://api.example.com/v1/items?limit=10

kind: string        — "text" or "base64"
content: string     — serialized body content
truncated: boolean  — true if body was cut off at max_response_chars
original_length: number — full byte/character count before truncation
json: any | null    — parsed JSON value if response was valid JSON, otherwise null