Stdio command path resolve

[mpaquettePax8]

Fix command path resolution in StdioTransport

Problem

When using command-line extensions in Goose, the command path was being used as-is, which could cause failures when starting a Goose session from different directories since the paths were relative to the working directory.

Changes

• Modified StdioTransport::resolve_command_path() to properly handle relative paths
• When a command path is provided:
  • If it's absolute, use it as-is
  • If it's relative, resolve it against the current working directory to get an absolute path

Testing

Test cases to verify:

1. Absolute paths work as before
2. Relative paths (e.g. index.js) are correctly resolved against the working directory
3. Starting a Goose session from any directory works with the same extension configuration