Add agent command group with create-from-dir support

[jason-rl]

• Add rli agent list/get/create/create-from-dir commands
• create-from-dir reads .runloopignore (gitignore syntax) for tar exclusions
• Falls back to sensible defaults (.git, node_modules, pycache, etc.)
• Reads agent.yaml for config (skills, webhooks, setup commands)
• Packages directory, uploads via object storage, creates agent

Description

Note: PR titles should follow Conventional Commits format (e.g., feat(devbox): add support for custom env vars or fix(snapshot): resolve pagination issue) as they are used for automatic release notes generation.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Code refactoring
• Performance improvement
• Test updates

Related Issues

Closes #

Changes Made

Testing

• I have tested locally
• I have added/updated tests
• All existing tests pass

Checklist

• My code follows the code style of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have updated the documentation accordingly
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published

Screenshots (if applicable)

Additional Notes