feat(python): add cli_args support to CopilotClientOptions for parity with Node.js SDK

[liuxiaopai-ai]

Summary

This PR adds cli_args support to the Python SDK's CopilotClientOptions, resolving the cross-SDK feature inconsistency reported in #381.

Problem

The Node.js SDK's CopilotClientOptions includes a cliArgs?: string[] field that allows users to pass extra arguments to the CLI executable. The Python SDK was missing this corresponding cli_args field, making it impossible to pass custom CLI arguments when using the Python SDK.

Changes

python/copilot/types.py

• Added cli_args: list[str] field to CopilotClientOptions TypedDict

python/copilot/client.py

• Store cli_args in client options (defaults to [])
• Insert user-provided cli_args before SDK-managed args in _start_cli_server(), matching the Node.js SDK behavior where cliArgs are spread before --headless, --no-auto-update, etc.

python/test_client.py

• Added TestCliArgs test class with 4 unit tests:
  • test_cli_args_defaults_to_empty_list
  • test_cli_args_stored_in_options
  • test_cli_args_empty_list
  • test_cli_args_single_arg

Node.js SDK Reference

The implementation mirrors the Node.js SDK behavior:

// nodejs/src/client.ts
const args = [
    ...this.options.cliArgs,  // user args first
    "--headless",
    "--no-auto-update",
    "--log-level",
    this.options.logLevel,
];

Closes #381