- Eliminated the OPENROUTER_API_KEY environment variable requirement from README.md and help_docs.py
- Updated rp/core/assistant.py to fall back to DEFAULT_API_KEY when no key is provided
- Added robust empty response and JSON decode error handling in rp/core/api.py
- Bumped version from 1.65.1 to 1.67.0 in pyproject.toml
- Updated CHANGELOG.md with version 1.67.0 entry documenting the API key removal
