Add context command for debugging repository context
Implement context debug command to help users understand repository
context resolution:
- Shows if current directory is a Tangled repository
- Displays owner (DID or handle), repository name, protocol
- Shows which Git remote is being used
- Provides helpful error messages when not in a Tangled repo
This is a debug/diagnostic tool that helps users verify their
context resolution is working correctly.
Includes comprehensive test coverage (4 tests) for success and
error cases.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>