Merge generate.py into agents.py for unified agent system
- Add get_muse_configs() to utils.py with has_tools/has_output filters
- Move generator functions (scan_day, generate_agent_output) to agents.py
- Update main_async() to route based on tools vs output config
- Simplify cortex.py to always spawn 'sol agents'
- Remove 'sol generate' command and delete think/generate.py
- Update all callers to use get_muse_configs()
- Fix tests to include 'tools' field for agent configs
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>