Function run_version_command 

pub fn run_version_command(command: &str) -> SoarResult<VersionCommandResult>

Execute a version command and return version, optional URL, and optional size.

The command is executed via sh -c and should output:

• Line 1: version string (required)
• Line 2: download URL (optional - if omitted, use url field with {version} placeholder)
• Line 3: size in bytes (optional)

Leading/trailing whitespace is trimmed from each line.