Add --version flag to CLI

[aidandaly24]

Description

The CLI currently has no way to check what version is installed. Add a --version flag that prints the current version from package.json (or pyproject.toml, depending on the project setup).

Requirements

• agentcore-cli --version should print the version number (e.g., agentcore-cli v0.1.0)
• Read the version from the project's package manifest file
• Exit with code 0 after printing

Acceptance Criteria

• --version flag prints version and exits
• Version string matches the value in the package manifest
• No other output or side effects when --version is used

Notes

This is a simple test issue to validate the loopy-symphony agent orchestrator pipeline.